Lone Druid
* 
Timbersaw: Lone Druid will have a hard time dealing with Timbersaw due to his tankiness and high Armor from 
Reactive Armor
Treant Protector
* Timbersaw can use his plethora of tree cutting abilities to level entire sections of the forest, making hiding in the trees more difficult for Treant Protector and his team.
* Timbersaw can easily cut down Treant Protector's 
Eyes In The Forest once his team has detection. He may even do it unknowingly due to the sheer destructive and chaotic nature of his abilities.
Additional:
* Not only are all of Timbersaw's active abilities capable of cutting down trees, but 
Whirling Death and 
Timber Chain also require it to be effective, counteracting both Treant Protector's Nature's Guise and Eyes in the Forest abilities.
Lone Druid
* 
Laser blinds Lone Druid, making his attacks miss.
Lone Druid
* 
Cold Embrace can protect allies from Lone Druid and the Spirit bear, who mainly deal physical damage
* 
Winter's Curse can turn Lone Druid and the Spirit Bear against his teammates.
Treant Protector
* Spiderlings melt away 
Living Armor almost instantly.
* The vision from Eyes In The Forest may prove dangerous for Broodmother, however.
Treant Protector
* Living Armor can be destroyed quickly with Ion Shell.
Lone Druid
* Chain Frost can deliver high amounts of damage to Lone Druid itself and his bear if they do not separate fast from each other.
Additional:
* 
Chain Frost will bounce between Lone Druid and his bear, forcing them to separate or suffer high amounts of damage.
Lone Druid
* 
Arcane Orb deals heavy damage to both Lone Druid and the Spirit Bear.
* 
Astral Imprisonment can prevent the Spirit Bear from attacking, which is Lone Druid's main damage output.
* 
Sanity's Eclipse deals heavy damage to Lone Druid.
Treant Protector
* Light Strike Array and Dragon Slave allows Lina to destroy trees, countering 
Nature's Guise and Eyes in the Forest.
* Lina has many tools to bypass Living Armor's protection.
Lone Druid
* Brewmaster can make the Spirit Bear a much smaller threat with Cinder Brew.
* Cyclone removes the bear from a fight so that his team can easily focus on the hero.
* While most heroes would be worn down by a Spirit Bear 
Radiance in the time it takes to kill Lone Druid, Brewmaster is protected in Primal Split.
Lone Druid
* Paralyzing Cask is likely to bounce between him and his bear every single time.
* Lone Druid's lack of mobility makes him vulnerable to Death Ward and Maledict.
Lone Druid
* Lone druid's bear attacks on Phoenix's 
Supernova Egg don't increase the hit count. Given that Lone Druid's main hero often doesn't have much farm, the Supernova Egg is less likely to get killed.
Treant Protector
* With Dual Breath, Liquid Fire and Macropyre Jakiro can quickly remove all Living Armor from a target.
* Ice Path allows Jakiro to prevent Treant Protector from using 
Overgrowth while staying at a safe distance.
Lone Druid
* 
Ghost Shroud can be use both offensively to slow Lone Druid or Defensively to prevent Lone Druid and The Spirit Bear from attacking him.
* 
Heartstopper aura burns the Spirit bear High HP over time. Additionally, it can deal decent damage to Lone Druid during his True Form.
Treant Protector
* All of Treant Protector's abilities are worth stealing, and Rubick is able to cast them with no animation time.
Treant Protector
* 
Corrosive Haze will reveal Treant Protector even when he is under the effects of Nature's Guise.
Lone Druid
* Huskar jumps on the hero without any problems, throwing the 
Summon Spirit Bear away from him and forbidding him to beat, which knocks down the regeneration of Lone Druid from the 
Spirit Link ability, in addition, Huskar instantly deals fatal damage to Lone Druid, in some cases he does not even have time to squeeze the 
True Form
Additional:
* Huskar jumps on the hero without any problems, throwing the Summon Spirit Bear away from him and forbidding him to beat, which knocks down the regeneration of Lone Druid from the Spirit Link ability, in addition, Huskar instantly deals fatal damage to Lone Druid, in some cases he does not even have time to squeeze the True Form
Lone Druid
* Tiny can be a serious problem for the distance between Lone Druid and his Summon Spirit Bear with his 
Toss ability, since he will throw one away from the other, giving his team the opportunity to deal with either the Summon Spirit Bear or Lone Druid himself
* Lone Druid will not always be in his True Form, since she has her own recharge, which is why Tiny can find him with a 
Shadow Blade or 
Blink Dagger and kill him in a second with a combination of 
Avalanche and Toss, due to the fact that Lone Druid has a very small health reserve without True Form
Additional:
* Tiny can be a serious problem for the distance between Lone Druid and his Summon Spirit Bear with his Toss ability, since he will throw one away from the other, giving his team the opportunity to deal with either the Summon Spirit Bear or Lone Druid himself
* Lone Druid will not always be in his True Form, since she has her own recharge, which is why Tiny can find him with a Shadow Blade or Blink Dagger and kill him in a second with a combination of Avalanche and Toss, due to the fact that Lone Druid has a very small health reserve without True Form
Lone Druid
* Reality Rift lets Chaos Knight bypass the Spirit Bear and jump onto Lone Druid.
* The Spirit Bear's lack of scaling means it dies quickly to Chaos Knight during the late-game.
Lone Druid
* Dazzle easily breaks the position of Lone Druid and his Summon Spirit Bear with his 
Poison Touch, As it always hits from afar and prolongs the slowdown on the Summon Spirit Bear, which is why he cannot catch up with Dazzle and treat his master with Spirit Link
* Dazzle helps his team survive the physical attacks of the Summon Spirit Bear thanks to the treatment from 
Shadow Wave and armor from 
Bad Juju, which can enable his team to kill Lone Druid
* The Lone Druid Summon Spirit Bear has a small amount of armor at the start of the game, because of Mid Dazzle, it can very much break through it and prevent Lone Druid from gaining an advantage at the very beginning of the game, giving his team the opportunity to overtake Lone Druid on items for killing him, by type: 
Spirit Vessel
Additional:
* Dazzle easily breaks the position of Lone Druid and his Summon Spirit Bear with his Poison Touch, As it always hits from afar and prolongs the slowdown on the Summon Spirit Bear, which is why he cannot catch up with Dazzle and treat his master with Spirit Link
* Dazzle helps his team survive the physical attacks of the Summon Spirit Bear thanks to the treatment from Shadow Wave and armor from Bad Juju, which can enable his team to kill Lone Druid
* The Lone Druid Summon Spirit Bear has a small amount of armor at the start of the game, because of Mid Dazzle, it can very much break through it and prevent Lone Druid from gaining an advantage at the very beginning of the game, giving his team the opportunity to overtake Lone Druid on items for killing him, by type: Spirit Vessel
Lone Druid
* Lone Druid and The Spirit Bear cannot burst down Bristleback due to 
Bristleback
* Bristleback can easily run to Lone Druid without any hesitation, with 
Viscous Nasal Goo to reduce armor and slow the Spirit Bear or Lone Druid and 
Quill Spray can deal damage to both Lone Druid and the Spirit Bear at the same time
Lone Druid
* Grimstroke's 
Soulbind will always reliably connect onto both of them if they are close together.
Lone Druid
* Unless Lone Druid purchases a 
Black King Bar for his Spirit Bear, Ensnare will easily kite the Spirit Bear.
* Song of the Siren allows Naga Siren and her team to completely bypass the Spirit Bear and hunt for the Lone Druid himself when starting a fight.
* Lone Druid's lack of innate AoE capabilities mean that Naga Siren's illusions have no problem against him.
Treant Protector
* Firefly will cut trees with ease, cleaning-up an area that's been enchanted with Eyes In The Forest, and potentially revealing a Treant under the effects of Nature's Guise.
* Batrider's DoT spells are also good versus Living Armor.
Treant Protector
* Invisibility reliant heroes: Heroes with invisibility abilities or those that have invested into invisibility items are hindered by Bounty Hunter's Track. Few examples of such heroes are:
Clinkz, 
Riki, 
Treant Protector, etc.
Treant Protector
* Heroes with invisibility will be detected by Thirst when they have low enough health: 
Bounty Hunter, 
Templar Assassin, Riki, Clinkz, 
Weaver, Treant Protector, 
Nyx Assassin.
Treant Protector
* Heroes with the capability of removing or destroying trees greatly hinders the effectiveness of Treant Protector's abilities: 
Batrider, 
Nature's Prophet, 
Lina, 
Enigma, 
Mars
Treant Protector
* Heroes that depend on disrupting fights with ability combos or big ultimate abilities are vulnerable to the long stun of Fiend's Grip: 
Disruptor, 
Death Prophet, Enigma, 
Faceless Void, 
Invoker, 
Lich, 
Magnus, Mars, 
Medusa, 
Outworld Destroyer, 
Phoenix, 
Puck, 
Queen of Pain, 
Shadow Fiend, Treant Protector, 
Underlord, 
Winter Wyvern, 
Witch Doctor, 
Zeus.
Treant Protector
* Melee heroes with low mobility can be kited and killed by Viper: Treant Protector, 
Kunkka, 
Alchemist, 
Troll Warlord, 
Wraith King, 
Tiny, 
Sven.
Lone Druid
* Riki: 
Smoke Screen can prevent Lone Druid from using True Form and Savage Roar, additionally it cause the spirit bear to miss on attacks which reduce the chances of getting rooted from it, with diffusal Blade, he can keep Lone Druid or the Spirit Bear inside the Smoke.
Lone Druid
* 
Pugna: 
Decrepify prevent the Spirit bear from attacking or protect allies from it.
Lone Druid
* Heroes that have doubles or clones such as 
Arc Warden, 
Meepo or 
Lone Druid are vulnerable to Muerta's 
Gunslinger.
Lone Druid
* 
Firestorm's percentage damage can quickly demolish the Spirit Bear's high HP
* 
Pit of Malice will allow allies to easily kite Lone Druid due to his low mobility
Treant Protector
* Heroes that provide vision will see Fiend's Gate coming: 
Techies, Templar Assassin, Treant Protector.
Lone Druid
* 
Mystic Flare can be used to effectively ignore the Spirit Bear entirely and burst Lone Druid during the early mid game.
* 
Concussive Shot and 
Arcane Bolt will provide vision of Lone Druid allowing for better chase in teamfights before the Spirit Bear can do too much damage.
* 
Ancient Seal denies the ability to transform into True Form and receive bonus HP from the skill.
Lone Druid
* Skywrath Mage also has a terrible time fighting against anything that isn't a hero. His skills are mostly target-based and he has terrible strength and agility, he can easily be kited or harassed by illusion-based heroes like 
Chaos Knight and 
Phantom Lancer, or by Heroes that summon other units like Lone Druid, 
Lycan and 
Beastmaster.
Treant Protector
* Monkey King is one of the few other heroes who can easily traverse through trees, counteracting Treant Protector's ability to hide in trees.
Treant Protector
* Heroes that can maintain vision on Monkey King can see when he uses Tree Dance: 
Bloodseeker, Treant Protector with Eyes In The Forest, 
Sniper, Weaver
Lone Druid
* Morphling can ignore Spirit Bear and shorten the distance to Lone Druid with Waveform.
* Morphling can use his nukes to burst Lone Druid down, provided he is not rooted/disabled by Spirit Bear beforehand.
Lone Druid
* Heroes who just want to farm and avoid Lone Druid early will find it very hard to do so when he starts knocking on towers: Templar Assassin, 
Phantom Assassin, 
Ember Spirit, 
Morphling.
Lone Druid
* True Form gives Lone Druid a huge amount of health that no amount of 
Ball Lightning will chip through.
* 
Entangling Claws can mean a very quick end to the Storm Spirit as it prevents him from using Ball Lightning all together.
* Storm Spirit is a single target nuker, with the Shard Lone Druid can always fear him away from himself or the bear, defending the target he does not go on. This is assuming he cannot try and proc his entangle or a potential 
Skull Basher.
Treant Protector
* If 
Storm Spirit is caught in an Overgrowth, he is shut down.
* With the exception of 
Electric Vortex, he won't be able to cast any relevant skill.
Lone Druid
* 
Omnislash spreads on both the bear and the druid, allowing them to survive.With enough levels,the bear can soak the ability alone and possibly dragging him to a dangerous location.
* Juggernaut cannot manfight the duo in the early game,because of their tankiness. If opposed in lane,Lone Druid can shut him down.
Treant Protector
* Heroes with abilities that can save teammates are also effective such as 
Shadow Demon, 
Dazzle, 
Oracle, 
Bane, Pugna, 
Tusk, Winter Wyvern, 
Io, Underlord, Treant Protector and 
Keeper of the Light.
Lone Druid
* Heroes who just want to farm and avoid Lone Druid early will find it very hard to do so when he starts knocking on towers: Templar Assassin, Phantom Assassin, Ember Spirit, Morphling.
Treant Protector
* Overgrowth prevents Phantom Assassin from using 
Blink Strike even through her spell immunity.
* Living Armor reduces Phantom Assassin's physical damage whenever she attempts to gank an allied hero.
Lone Druid
* Lone Druid has a very large reserve of health against Invoker abilities, this allows him to survive a large number of attacks from Invoker and kill him, also Entangling Claws reveal invisibility from 
Ghost Walk, which allows the Lone Druid team to catch the popular QW-Invoker
Additional:
* Lone Druid has a very large reserve of health against Invoker abilities, this allows him to survive a large number of attacks from Invoker and kill him, also Entangling Claws reveal invisibility from Ghost Walk, which allows the Lone Druid team to catch the popular QW-Invoker
Treant Protector
* Treant can give chase should Hoodwink attempt to 
Scurry away, and 
Nature's Grasp can slow her down so Treant Protector's teammates can pin Hoodwink down.
Treant Protector
* Treant Protector can usually scout out Magnus in the trees with Eyes in the Forest and disrupt his initiation attempts. He can also counter Magnus' initiation with Overgrowth.
Lone Druid
* Lone Druid has a huge reserve of health on the Summon Spirit Bear and a quick regeneration of his health with the help of Spirit Link, which makes the Puck's magical abilities useless, since they cannot break through such a large pool of health
* The ability of the Summon Spirit Bear and in the True Form of the Lone Druid Entangling Claws allows you to catch Puck when he released the 
Illusory Orb, since Puck will not be able to apply 
Ethereal Jaunt during the root action
Additional:
* Lone Druid has a huge reserve of health on the Summon Spirit Bear and a quick regeneration of his health with the help of Spirit Link, which makes Puck's magical abilities almost useless, since they cannot break through such a large pool of health.
* The ability of the Summon Spirit Bear and in the True Form of the Lone Druid, Entangling Claws, allows him to catch Puck when it releases the Illusory Orb, since Puck will not be able to apply Ethereal Jaunt during the root.
Treant Protector
* Anti-Mage relies on blinking and attacking. Overgrowth prevents both.
* Be wary that he will eventually farm up a 
Manta Style that fully dispels Overgrowth. Good players will wait for your ultimate to use their manta. Perhaps an ally has a silence or similar that would force him to use his manta before your ultimate.
Treant Protector
* Another hero heavily based on attacks and no mobility, being an easy prey for Treant strong disarms and motion reduction skills.
Lone Druid
* Silencer's disables are useless on Lone Druid since he is more reliant on physical attacks rather than spells.
* Silencer has poor mobility so Lone Druid can run him down.
* Lone Druid's Shard will remove most of Silencer's spells once used.
Lone Druid
* Savage Roar interrupts 
Starbreaker.
* Dawnbreaker is a slow moving hero. Although tanky, Lone Druid can eventually wear her down with his better movement speed.
Treant Protector
* Nature's Grasp severely slows down Spirit Breaker, reducing effects of Charge of Darkness and Greater Bash.
* Living Armor can mitigate a large portion of Spirit Breaker's damage since his attacks are slow.
* Treant Protector can also counter-initiate against Spirit Breaker with 
Leech Seed, Overgrowth and with his root from 
Aghanim's Shard upgraded Nature's Guise before he manages to escape.
* 
Aghanim's Scepter gives Treant Protector access to Eyes In The Forest ability, which allows him to turn trees into wards that provide vision, allowing him to keep his allies warned about Spirit Breaker's attempts to gank them. Eyes In The Forest will also trigger Overgrowth if Spirit Breaker is in range of the tree affected by it.
Additional:
* Spirit Breaker's slow attacks cannot harm a hero shielded by Living Armor.
Treant Protector
* Living Armor and Leech Seed can be used to save a hero from a 
Relocate gank.
* Overgrowth can be used to cancel escape attempts with Relocate.
* Once Treant Protector buys Aghanim's Scepter, he will gain access to Eyes in the Forest, that will allow him to enchant a tree which will grant him unobstructed vision in that location, allowing him to keep his allies alerted on Io and his 
Tethered's attempts to gank them, and which can also allow Overgrowth to damage them and root them if they are within a 800 radius of an tree affected by Eyes in the Forest.
Lone Druid
* Alchemist likes to farm fast and be ahead, unfortunately Lone Druid likes to do the same by taking towers.
* 
Acid Spray will never prove a threat to Lone Druid or his Spirit Bear.
* 
Chemical Rage may not prove so useful once Lone Druid procs entangled keeping him in place.
* 
Monkey King Bar is a very good choice on Lone Druid's Spirit Bear and it directly counters any potential Radiance from Alchemist.
* 
Assault Cuirass is another very good Spirit Bear item that further makes Alchemist vulnerable to physical damage, which is all Lone Druid does.
* Alchemist is not the kind of hero who wants to go on single target summon units, by the time he has killed the Spirit Bear his teammates might had already been slayed by his teammates. Not to mention Lone Druid can just resummon it, even if he is successful.
Treant Protector
* Clinkz will often roam the map alone, and Treant Protector's Nature's Guise allows him to set up kills with his allies on Clinkz from invisibility.
* Treant Protector's very high damage allowing him to trade hits or contest last hits with Clinkz, while Living Armor can be used to sustain the harass.
* Living Armor protects any of Treant's allies ganked by Clinkz.
* In teamfights, Treant Protector's Overgrowth can disarm Clinkz, preventing him from turning invisible and holding him in place even if he has a Black King Bar.
* Leech Seed slows Clinkz, preventing him from repositioning or fleeing away from danger.
Lone Druid
* Lone Druid becomes unkillable and impenetrable for Ember Spirit on the central line, as it has a huge reserve of health from the Summon Spirit Bear and a large regeneration from Spirit Link, which is why 
Sleight of Fist practically does not break through either one or the other on the line, and Lone Druid at this time can easily expel Ember Spirit from the line, push and gain gold and level
* Entangling Claws and 
Savage Roar abilities completely disable Ember Spirit's ability to dodge abilities or get out of an unpleasant fight for him on 
Fire Remnant, which can give the Lone Druid team the opportunity to kill him
Additional:
* Lone Druid becomes unkillable and impenetrable for Ember Spirit on the central line, as it has a huge reserve of health from the Summon Spirit Bear and a large regeneration from Spirit Link, which is why Sleight of Fist practically does not break through either one or the other on the line, and Lone Druid at this time can easily expel Ember Spirit from the line, push and gain gold and level
* Entangling Claws and Savage Roar abilities completely disable Ember Spirit's ability to dodge abilities or get out of an unpleasant fight for him on Fire Remnant, which can give the Lone Druid team the opportunity to kill him
Lone Druid
* Because of his weak laning phase, Lone Druid absolutely overpowers him in the early to mid game. Lone Druid also directly counters most of his abilities.
* 
Flux is nullified when the Spirit Bear is nearby.
* 
Spark Wraith can get soaked by the bear.
* Lone Druid can easily go inside 
Magnetic Field and punish Zet.
Treant Protector
* Heroes with powerful rooting abilities will disable most of Pangolier's skills, a bonus point if it pierces spell immunity since it will also be able to stop Pangolier during his Rolling Thunder: Treant Protector, Meepo, 
Crystal Maiden, 
Dark Willow, Underlord, 
Naga Siren
Treant Protector
* Overgrowth has a great duration, which prevents the units caught from attacking, moving and Blinking. Heroes like Storm Spirit, 
Mirana, 
Anti-Mage and others won't be able to do much if they're caught.
Lone Druid
* Heroes who just want to farm and avoid Lone Druid early will find it very hard to do so when he starts knocking on towers: Templar Assassin, Phantom Assassin, Ember Spirit, Morphling.
Treant Protector
* Clinkz, Sniper, Lone Druid, Troll Warlord, 
Legion Commander and Wraith King are some of the Heroes that base themselves on attacks with little or no spell power, so they suffer in the grassy hands of Overgrowth.
Lone Druid
* Lone Druid's early game is good against slow, squishy supports since his bear is very strong early game and an Entangling Claws proc almost always guarantees a kill: 
Ancient Apparition, Crystal Maiden, 
Shadow Shaman, etc.
Treant Protector
* Treant Protector grants protection against his attacks with Living Armor and his ultimate, Overgrowth is a massive AoE disarm and root that pierces spell immunity, causing trouble to Lycan. You will find yourself in need of an ally's dispel or forced to pop Black King Bar for its dispel.
Additional:
* Lycan has no kind of teleport, being only able to walk, and heavily relies on his attacks. As Overgrowth roots and disarms the targets, Lycan can't do much in an overgrowth field.
Lone Druid
* Primal Beast is mostly played in the offlane role, so picking a carry who can escape from him is essential. Heroes such as Troll Warlord, Lone Druid and Outworld Destroyer, or generally any carry with a stun, slow or ability to fight back will stop him from having the good start he needs.
Treant Protector
* Clinkz, Sniper, Lone Druid, Troll Warlord, Legion Commander and Wraith King are some of the Heroes that base themselves on attacks with little or no spell power, so they suffer in the grassy hands of Overgrowth.
Lone Druid
* Lone Druid's early game is good against slow, squishy supports since his bear is very strong early game and an Entangling Claws proc almost always guarantees a kill: Ancient Apparition, Crystal Maiden, Shadow Shaman, etc.
Lone Druid
* Nukers who have set amounts of damage will really struggle against Lone Druid especially in True Form: Puck, 
Void Spirit, Mars.
Treant Protector
* Treant Protector's Living Armor will also negate Tidebringer's damage.
Lone Druid
* Chaos Knight, Lone Druid, Meepo and Arc Warden can be hard targets since Shadow Demon's spells are ill-suited to fight many enemies at once.
Treant Protector
* Heroes with global abilities can give Legion Commander's opponent an edge in Duels from anywhere on the map: Nature's Prophet, Ancient Apparition, Zeus, Invoker, Treant Protector
Lone Druid
* Heroes who can fight back easily are not ideal matchups for Sven, such as Troll Warlord as mentioned above, Lone Druid and Templar Assassin.
Lone Druid
* Lone Druid's early game is good against slow, squishy supports since his bear is very strong early game and an Entangling Claws proc almost always guarantees a kill: Ancient Apparition, Crystal Maiden, Shadow Shaman, etc.
Treant Protector
* Clinkz, Sniper, Lone Druid, Troll Warlord, Legion Commander and Wraith King are some of the Heroes that base themselves on attacks with little or no spell power, so they suffer in the grassy hands of Overgrowth.
Lone Druid
* Besides Lone Druid and Meepo, Doom is potentially good versus every hero since Doom will render any hero helpless for up to 16 seconds. This is particularly true for fragile heroes that heavily rely on mobility to stay alive.
Lone Druid
* Lone Druid is essentially two heroes. Dooming one over the other still leaves Lone Druid or his bear able to do their job during a fight. Additionally, Lone Druid is not hindered as much as other heroes by the silence and mute of Doom since the hero relies more on attacks than abilities.
Additional:
* Doom will be very hestitant to use 
Doom on the Spirit Bear, and using it on Lone Druid himself will not stop the bear from attacking him especially if True Form has already been used.
* 
Devour does not work on the Spirit Bear and pushes the lane so Lone Druid can safely farm under tower.
Treant Protector
* Heroes with the capability of removing or destroying trees greatly hinders the effectiveness of Treant Protector's abilities: Batrider, Nature's Prophet, Lina, Enigma, Mars
Lone Druid
* Nukers who have set amounts of damage will really struggle against Lone Druid especially in True Form: Puck, Void Spirit, Mars.
Treant Protector
* Nature's Prophet's Nature's Call can destroy trees that Treant Protecter is hiding in, revealing him.
Lone Druid
* Once caught in Bear's Entangle, Nature's Prophet cannot escape with 
Teleportation.
Lone Druid
* Illusions and summons are double-edge sword type of matchup for Luna. On one hand, they can tank damage from Eclipse, but on the other hand, she can easily clear them before Eclipse with Moon Glaives. Examples include 
Spectre, Shadow Demon, Phantom Lancer, Naga Siren, Chaos Knight, 
Terrorblade) or bring other units into the fight (such as Nature's Prophet, Lone Druid, 
Chen, 
Enchantress, Meepo and Arc Warden).
Lone Druid
* Heroes that create illusions: Spectre, Shadow Demon, Phantom Lancer, Naga Siren, Chaos Knight, Terrorblade) or bring other units into the fight (such as Nature's Prophet, Lone Druid, Chen, Enchantress, Meepo and Arc Warden) can cause Eclipse to strike the illusions/summons unintentionally. However, in many cases Moon Glaives can resolve this issue and eliminate them before activating Eclipse, but that will require lots of farming for right-click items.
Lone Druid
* Lone Druid and his Spirit Bear lack mobility, and are easy overwhelmed after being slowed by
Diffusal Blade.
Savage Roar is useless since Phantom Lancer can return to fight him again with his 
Phantom Rush.
*
Treant Protector
*
Doppelganger can dispel Leech Seed. It can also destroy large amounts of trees, counteracting Nature's Guise and Eyes in the Forest.