Charged pulse blasters are a protoss technology used by the Tal'darim. When the Tal'darim looted colossi from their kindred, they replaced the thermal lance armaments with charged pulse blasters, creating wrathwalkers. This made them effective at destroying priority targets.
References[]
Blizzard Entertainment. StarCraft II: Legacy of the Void. (Activision Blizzard). PC. War council (in English). 2015.