Standard: The build you'll mainly use on Gul'dan. Brings strong waveclear and enormous late game damage. Take Bound by Shadow when Morales or Auriel is on your team, otherwise go for Hunger for Power.

Q build: Acceptable build against a heavy frontline or when the enemy team tends to clump up. For example, when Auriel is their support, or when Johanna is on your team. Finishing lvl 1 quest enables great poke damage.

Rain of Destruction: A risky build, but devastating if executed well. Requires very strong map awareness. Strong on Warhead Junction for sieging, because of it's incredible size. Do NOT take this build when the enemy has a lot of dive or when you have a weak frontline, as you'll be channeling for 7 seconds leaving you vulnerable. Demonic circle allows you to RoD at will, as you have an instant escape. Opens up possibilities to backdoor or to melt keeps. Hunger for Power and Darkness within grant this ability 40% extra AP, which makes it a devastating sieging tool.