The wrathwalkers are colossi that were found and reactivated by Tal'darimascendants in search of superior firepower. They had their thermal lances replaced with charged pulse blasters, making them powerful against priority targets.
In Legacy of the Void, the wrathwalker is one of three robotic siege units the player can use, along with the colossus and the reaver. Despite being a colossus variant, however, the wrathwalker is a very different unit in combat. Instead of the colossus's splash damage, the wrathwalker deals heavy damage to single targets, making it better for fighting smaller numbers of powerful enemy units instead of swarms of smaller units. Another key difference is that the wrathwalker can attack ground and air units, allowing it to be more effective against a mixed enemy force. It can also attack while moving, making it easier to keep them safe from retaliation while still damaging targets. However, it has a substantially higher cooldown than the colossus or reaver. Wrathwalkers, like colossi, can still be hit by anti air.