[quote=@Intrepid]
<Snipped quote by Techspert>

You're thinking on the right track, here, but let me guide you a bit more. He needed the vast number of deaths to be in such a concentrated area, as he can't expand his influence across pretty much all of Existence to take advantage of that... But he can now, and he's growing ever-stronger because of it.
[/quote]

*Shrugs*
Give me the physical process in which he gains energy from death and I'll work out something to break it.