* Firefly can be used to clear Nature's Prophet's treants and allowing to jump on Sprout.
* Flaming Lasso prevents Nature's Prophet escaping from Teleportation.

* Undying's Tombstone will cheerfully chew through treants, incidentally netting you some extra income during fights.
* The above interaction tends to ensure that skirmishes are heavily populated with units, thereby buffing Soul Rip

* Decay, Soul Rip and Flesh Golem all deal magical damage which ignores Bulwark.
* Decay reduces Mars' natural strength, and therefore his health pool which is what he relies on to trade effectively in lane.

* Sticky Napalm slows turn rate, making it difficult for Mars to control the direction he is facing to activate Bulwark.
* Flaming Lasso disables Mars while enemies re-position themselves behind Mars to avoid Bulwark.

* Undying's Decay is a dangerous ability against Bristleback, as it makes him more vulnerable and reduces his tankiness.
* Undying's Tombstone together with Flesh Golem can slow Bristleback down significantly.

* Batrider's turn rate slow from Sticky Napalm makes it harder for Bristleback to keep his back towards the enemy.

* Decay's stacking strength reduction makes Axe much less dominant in lane.
* Tombstone's zombies take no damage from Counter Helix, and will continuously put Axe's Blink Dagger on cooldown until dealt with.

* Heroes who can slow and kite Axe will severely inhibit his presence in fights: Bristleback, Crystal Maiden, Batrider, Arc Warden, Winter Wyvern, Clockwerk

* Undying can use Decay not only to reduce Sven's maximum health, but also to reduce the damage he can deal with his ultimate.
* Zombies spawned by Tombstone together with Flesh Golem slow Sven down significantly. Landing Sven's powerful but somewhat slow right-click on Tombstone would be a waste.

* Batrider often hides in the trees to initiate on a target. As such, he has a slight edge against heroes that have no scouting tools and cannot see him coming, such as Lion or Sven.

* Firefly allows Batrider to gain vision of Monkey King while he is on an tree, as well as destroying any nearby trees, denying Monkey King spots to jump to, or causing him to fall.
* Sticky Napalm's turn rate slow makes it significantly more difficult for Monkey King to jump from tree to tree and gain Jingu Mastery stacks. It also reveals Monkey King while he is on a tree.
* Flamebreak and Flaming Lasso enable Batrider to remove Monkey King out of Wukong's Command.
Additional:
* Firefly destroys trees and can turn Tree Dance into a free four second stun.

* Sticky Napalm slows Chen and amplifies Batrider's damage.
* Flamebreak and Firefly can deal heavy damage to Chen and his creeps.
* Flaming Lasso pulls Chen away from his creeps, often to certain death.
Additional:
* Sticky Napalm slows Chen and his creeps and Flamebreak and Firefly can deal heavy damage to them.
* Flaming Lasso pulls Chen away from his creeps, often to certain death.

* As long as Batrider is under the effects of Firefly, he can safely fly over mines.
* Sticky Napalm also punishes low mobility heroes that like to kite, such as Techies, by lowering their turn rate dramatically. This can also potentially delay Techies' Blast Off! if Techies tries to cast Blast Off! in a direction he's not currently facing.
Additional:
* As long as Batrider is under the effect of Firefly, he can safely fly over Proximity Miness (He does not receive vision over the mines).

* Decay can be good against Centaur Warrunner, as reducing the health of Centaur can make Double Edge risky.
* His zombies do not proc Return.

* Many stacks of Sticky Napalm, combined with Flamebreak and Firefly, allows Batrider to destroy illusions from Mirror Image.
* If Batrider can manage to destroy all illusions from Naga Siren, he will be able to use Flaming Lasso on the real one, and will be able to drag her toward his team, potentially preventing Naga Siren to escape with Song of the Siren.
Additional:
* Many stacks of Sticky Napalm, combined with Flamebreak and Firefly, allows Batrider to destroy illusions from Mirror Image.
* If Batrider can manage to destroy all illusions from Naga Siren, he will be able to use Flaming Lasso on real one, and will be able to drag her toward his team, potentially preventing Naga Siren to escape with Song of the Siren.

* Batrider's abilities are designed to deal damage over time, burning through Templar Assassin's layers extremely quickly. Flamebreak applies 7 instances of damage, burning through the entirety of Refraction, and Firefly applies damage on the place, forcing her to either get out of Meld and be attacked or stay in place or be incinerated.
Additional:
* Batrider's DoT damage quickly removes Templar Assassin's Refraction and can damage her during Meld.

* Winter Wyvern cannot handle the Zombies created by Undying's Tombstone very well. In most situations, Zombies will have more movement speed than her.
* Undying can gain one or two easy Decay stacks on an ally in Cold Embrace. The ally will still take the damage as well.
Additional:
* Winter Wyvern cannot handle the Zombies created by Tombstone very well. In most situations, Zombies will have more movement speed than her.
* Undying can gain one or two easy Decay stacks on an ally in Cold Embrace. The ally will still take the damage as well, since it is magical.

* Due to Spirit Breaker's low attack speed, Tombstone is problematic for Spirit Breaker.
* The zombies summoned from Tombstone apply a stacking movement speed slow, which can significantly reduce Greater Bash's damage.
* Soul Rip and Decay allows Undying and his allies to survive from incoming ganks of Spirit Breaker.

* Undying saps strength from heroes with Decay, and Ogre Magi's high strength gain will allow Undying to steal more and more strength, becoming stronger with each use.
* Due to the Strength steal from Decay, Undying is normally very tanky, and has high health, making it harder for Ogre Magi to kill him.

* Spectre must chase for kills and relies on movement speed for mobility in fights, and has no way to counter the Tombstone zombies.
* The potency of Soul Rip can be increased from nearby illusions from Haunt.
* Decay will shut down Spectre during the laning phase by effectively cutting down her initial health pool.
Additional:
* Spectre must chase for kills and relies on movement speed for mobility in fights, and has no way to counter the Tombstone zombies.
* The potency of Soul Rip can be increased from nearby illusions, so Undying can use Haunt against Spectre.
* Early game Decay will make Spectre easy to shut down in lane.

* Heroes that can gain vision over trees to catch Tinker: Invoker, Shadow Demon, Batrider

* Generally, any fragile heroes will have a hard time dealing with Undying's tankiness, and even more so if Decay is used on them. Some examples are Crystal Maiden and Witch Doctor.

* Anti-Tank heroes like: Razor, Necrophos, Undying.

* Batrider often hides in the trees to initiate on a target. As such, he has a slight edge against heroes that have no scouting tools and cannot see him coming, such as Lion or Sven.

* Heroes with abilities that can pull Lina out of position can easily bring her to their team mates, like Batrider with Flaming Lasso and Pudge with his Meat Hook.

* Heroes with other kind of disables that pierce spell immunity can hold Pangolier in place during Rolling Thunder: Axe, Beastmaster, Enigma, Magnus, Pudge, Batrider, Bane, Winter Wyvern

* Heroes with a slow attack rate will find themselves struggling to take out Tombstone, like Doom.

* Any hero who can counter-initiate in anticipation without getting caught in Reverse Polarity: Sven, Omniknight, Enigma, Luna, Naga Siren, Mars, Jakiro, Venomancer, Elder Titan, Faceless Void, Rubick, Keeper of the Light, Pugna, Invoker, Spectre, Alchemist, Treant Protector, Lina, Oracle, Zeus, Shadow Shaman, Phoenix, Razor, Huskar, Batrider, Kunkka, Tidehunter, Wraith King, Sand King.

* For the same reason, he has to be slightly more cunning when playing against heroes that can scout the treeline, such as Ancient Apparition and his Ice Vortex and Shadow Demon and his Shadow Poison.

* Generally, any fragile heroes will have a hard time dealing with Undying's tankiness, and even more so if Decay is used on them. Some examples are Crystal Maiden and Witch Doctor.

* Enigma's left level 25 talent (increasing the Eidolon count from three to eleven) powers up Undying's Soul Rip.

* 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

Additional:
* 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,

* Heroes with stronger lane presence that can threaten to kill him: Batrider, Juggernaut, Ursa, Monkey King, Razor.

* Heroes with disables that go through spell immunity can end Bloodseeker before he has the chance to do anything: Batrider, Beastmaster

* For the same reason, he has to be slightly more cunning when playing against heroes that can scout the treeline, such as Ancient Apparition and his Ice Vortex and Shadow Demon and his Shadow Poison.

* Batrider's Flaming Lasso can become annoying when Batrider has a team nearby to kill the disabled Meepo. His Firefly is also good AoE damage, which when stacked with sticky napalm (which is AoE too and can hit all Meepos), he becomes a very formidable target.

Additional:
* Flaming Lasso is the perfect tool to isolate a single Meepo and focus him.