Here, you will need to fight two major enemies. The Realm of Terror: After suffering enough damage (about 65%), Diablo stuns you and shunts you off to his Realm of Terror, essentially a dark and shadowy counterpart of the Crystal Arch you've been fighting him in, but without Healing Wells. Used automatically if player gets caught into the Bone Prison. Teleport: Used both to get closer to ranged characters and to avoid melee combat.

Note that Bone Prison stuns the character instead of immobilizing them, so Teleporting out will not be possible. Some defensive abilities can be used while grabbed. This attack cannot actually kill a hero (reducing to 1 Life instead), but is often followed by a Slash. If caught in it, Diablo will teleport to you, grab you by the throat and drain your health before slamming you into the floor.

Bone Prison: Creates a series of black pools on the ground, trying to create them as close to the player as possible.

Fire Wall: Creates a fast-moving wall of fireballs, similar to Flame Circle, but with an arc and moving faster and further.

Flame Circle (similar to Diablo II equivalent): Creates a circle of ground-based fireballs, each doing average Fire damage, moving in all directions.

Fireball: A ground-based missile that, upon reaching any target or obstacle, explodes into a pool of fire, doing high Fire damage over time if you're caught in it.

Slash: A rapid melee strike with Diablo's hoof, claw, armblade or tail, dealing average Physical damage.

While he looks pretty agile, he is actually moving and attacking very slowly, compensated by his high damage and ability list. I Am Legion: Diablo has five major attacks over the course of the battle, along with some supporting abilities. There are two Health Wells on the left and right sides of the central ring, but they are not available in phase 2. The battle consists of three major phases, each of which can last as long as needed (as Diablo has no enrage timer). Followers cannot go with you to the fight against him (except in Adventure Mode), so prepare yourself accordingly. With all seven Evils embodied in him, he is not an easy fight.

The final battle with Diablo takes place atop the Crystal Arch of the High Heavens after fighting your way through the Silver Spire to reach the Pinnacle of Heaven at the end of Act IV.

Diablo iii tyrael act iv