Who Is Killy in Blame!?
Almost nothing about Killy is ever explained, and that is the point. He enters Blame! already ancient, already armed, already walking. His quest has one sentence: find a human who carries the Net Terminal Gene, the genetic marker that once let people access the Netsphere, the control network of the City.
The marker is lost. A retrovirus released by a cult called the Order deleted it from humanity, and without it no one can order the Builders to stop building or the Safeguard to stop killing. Killy’s search is therefore not a treasure hunt. It is the only remaining way to switch the world off safe mode. His weapon is the Gravitational Beam Emitter, a handgun that fires a line of annihilation and is one of the only things that can pierce the Megastructure itself.