"Why not? One might ask, why did the spell the necromancer casted affected only a certain portion of us?" he asked, form Ling. "There are some undead, whom were the first to die from the plague. And yet even those, whom died with me and the same moment remain still buried."

"We don't believe that it was our destiny, to become undead. Rather...its that we have some purpose to serve, the certain picked one of us," he spoke.

(As an idea for a plot. How about angels attacking the world?)