Compared to the other bosses on Inferno difficulty, Azmodan is by far the easiest to defeat because he can be killed with a variation of builds and/or gear. Whether you’ve been stacking vit/resists or want to continue as a glass cannon, defeating Azmodan to get access to Act 4 is entirely about movement and reaction times.
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This build will allow the Witch Doctor to burn down a large percentage of Azmodan’s health before he has the opportunity to begin casting lazers. While Pierce the Veil increases the cost of spells, the mana return from the Rain Dance skill rune is more than enough to sustain chain casting Zombie Bears during phase 1 and the initial stages of phase 2. Once Big Bad Voodoo has stopped, switching to Poison Dart with the Splinters skill rune will be the primary attack until BBV has refreshed.
Spirit Walk with Jaunt and Horrify with Stalker provide the WD with 2 ways of increasing run speed – both very useful in this fight. While you may be inclined to use these to run away from Azmodan’s meteors, it’s important to note that it’s a time based attack and will not simply land on you because you’re near it.
By using BBV at the beginning of the fight, you can avoid the first meteor by using SW and side stepping any future ones. Running away simply reduces the initial amount of DPS you’re able to lay on him while BBV is up. The Tribal Rites passive will ensure it’s refreshed sooner so that you can finish him off quickly towards the end of the fight – which can become difficult if you’re not prompt in destroying his gateways that spawn minions (or if you choose to ignore them).
The speed boost from the Stalker skill rune is just enough to allow you to move out of the rain of bones/body parts AOE he casts – you’ll get a moments warning prior to him casting it if you look carefully at the ground.
The most difficult part of the Azmodan fight is avoiding the pools he casts. While at first it would appear they are cast directly under your feet, that’s really not the case. The first 3 pools are untargeted and random – continue DPSing Azmodan during this. Once the 3rd pool is about to finish enlarging, you should move away and begin a 5 second count down.
The trick to not getting stuck in the center of his pools is to change your direction at the very last moment (essentially every 5 seconds). The pools will then appear where you would’ve been had you not quickly changed your direction. It may take you a little while to get the hang of it but it is very simple to avoid. Running to outside and turning direction back towards the center is also helpful in reducing the amount of ground the pools take up. SW and the Horrify/Stalker speed boosts will give you a small margin of error should you mess things up.
Given the Azmodan fight is about quick movement and reaction times, it’s far more dependent on these 2 things than which build you’re using.