As an assassin Illidan's role is meant to be a damage dealer. His kit equips him to be highly active with maximum maneuverability. Dive allows him to close distance and slow a single target, Sweeping Strikes allows him to damage enemies in a line while quickly closing (or increasing) distance, and Evasion increases his survivability by evading auto attacks. Unfortunately Illidan suffers from a low health pool, low auto attack damage, and relatively low ability damage. Basically he does not have great burst potential, but he lacks the survivability to deal damage over the course of a longer fight.

Most builds I've seen attempt to maximize his assassination potential taking talents such as Battered Assault, Marked for Death, and Blood for Blood. This type of a build turns Illidan into a glass cannon, but one who will generally trade at a one-to-one due to being melee and lacking survivabilty.

Illidan excels at one-vs-one fights, but due to the nature of HotS maps and the importance of objectives, this is rarely possible. The goal of this build is to play Illidan as a sustained damage dealer who can use his low cooldown, maneuverable kit to win through decision-making as opposed to an explosive one-for-one trade. I've found great success focusing on sustained damage and self-healing to better leverage Illidan's ability to disrupt and increase his team-fight applicability.

Many of these talents work in tandem with one another so I will introduce them as such when necessary.

--- TANDEM TALENTS ---
Immolation & Hunter's Onslaught: These two talents taken at level 4 and 16 respectively give Illidan the opportunity to deal sustained damage while bolstering his ability to self-heal. At level 20, Immolation will do 77 damage per second to each target in range. This also equals 11.55 health per second per target from Hunter's Onslaught. In addition to this synergy, Immolation opens the opportunity for Illidan to capture the Knight camp at level 4 by himself.

First Aid + Metamorphosis: These two talents taken at level 7 and 10 constitute a greater commitment to keeping Illidan alive during a fight. The added health bonus from Metamorphosis will amplify the effect of First Aid. First Aid also allows Illidan to stay fighting early game whether it is after a skirmish, a merc camp, or clearing a wave of minions. Metamorphosis also holds synergy with Hunter's Onslaught. At level 20, Metamorphosis will deal 400 damage to each target hit and heal for 60 health per target. This may seem minuscule, but when Metamorphosis and First Aid are used in tandem, that extra health gives time for First Aid to tick.

--- OTHER TALENTS ---
Shadow Shield: This talent bolsters Illidan's early-game survivability which is crucial. Evasion itself does little to defend Illidan early game as auto-attack damage is minimal. Additionally, because lanes are small at the start of the game, Illidan's ability to chase is marginalized. Thus he is relegated to being a poking hero early on. Later in the game, by level 20 Evasion will give Illidan a ~300 health shield when every little bit helps.

Sixth Sense: Reducing 50% of ability damage not only increases Illidan's survivability, but perhaps opens him to be a bit of a sponge in fights. It's no secret Illidan is squishier relative to other melee heroes so he garners attention as soon as he engages. Absorbing abilities then using Metamorphosis and/or Dive/Sweeping Strikes to temporarily disengage can greatly reduce the damage potential of the enemy team. This type of tactic is playing with fire though, generally speaking it just helps Illidan stay alive.

Demonic Form: I'm not sold on this talent, a lot of the time I take Bolt of the Storm instead, but for the purposes of this guide I decided to stick with it. The increase in attack speed is a significant boost to his damage, healing, and CDR through his passive. The downside is your inability to mount until you get killed. On larger maps (Garden of Terror) or ones that stress mobility (Dragon's Shire) I'll often take Bolt of the Storm just so I can mount later. Fury of the Storm is ok, but we focus on Illidan's ability damage in this build and less on his auto-attack.

This build allows you to play Illidan the way I now think the developers intended him to be used. Instead of focusing on his damage and burst potential, Illidan becomes a hero who can slow fleeing heroes, avoid crowd control abilities via Dive, and mitigate the opponent team's damage output through Evasion with Sixth Sense. This build is also somewhat queue-immune as I often am placed in a group with no warrior, becoming "the initiator" in our team.

Illidan does not follow an A,B,C style of gameplay so it is difficult to articulate how to play him. So I've listed a series of things to keep in mind while using him:

* Dive flips you over your target which is incredibly useful in setting up body blocks and slowing an enemy who is retreating
* Sweeping Strikes lets you dash through targets which also is useful in setting up body blocks
* Use Dive to clear ground-based CC such as Malfurion, Arthas, Tyrande, Gazlowe, Kerrigan, etc.
* You're immune while casting Metamorphosis, if you're playing against a trigger-happy Uther, ETC, or any hero with a non-targeted AOE ability you can often bait out these abilities and then completely avoid them
* At level 4 you can kill the Knights camp by focusing the healer first then each melee knight. Be sure to have all targets getting hit with Immolation and use your abilities as they come off cooldown
* When doing a Dive/Sweeping Strikes combo make sure to weave your auto-attack between the abilities

Thanks for reading this, I'd appreciate any feedback on both the quality of the guide and playing Illidan. Happy hunting!