He is really pissed off, because someone has ripped off his hips and legs, took his guts and spine out and mounted a kind of machinery at its place. The machinery in his body enables him to fly and he hurls very fast fireballs at you. They are not very accurate, but for that reason he hurls six of them at once.
It sounds like it sort of acts like the Scrag from Quake, at least to me anyways, and just between you and me I think the name could use some work. Visit the Facing Hell website for more infos and media.