How do you do a devastator attack in prototype?

Answer 1

First of all, you need to buy the Devastator moves from the Upgrades menu. Then, get enough health (biomass) by consuming other infected/military/civilians until your health bar is not only red, but also has some blue at the end. Once these two things are done, you must hold the combination of TWO buttons for the particular Devastator until it activates. For example, if you wanted to use the Tendril Barrage Devastator, hold both Triangle+Circle (on PS3) for about 3 seconds and it'll activate. The Devastator moves are actually pretty cool once you get them working.

Best of luck!