[quote=kapuchu]
I was sure he talked to a Cultist about "twenty corpses payment instead of 10" or something like that... Him wanting more from a deal they had than usual.
[/quote]

Sorry I thought you were asking whether he was Necro'ing ponies for the cult the first time I read that, my bad. 

That was his attempts at perfecting the process of Ressurectionism and the machinery involved in it. Also they weren't exactly dead and the cult didn't exactly understand what he was doing with them, which was honestly pretty brutal anyway. Grunge was one of those ponies in the machinery test, and lets just say that he's different from the others because he wasn't made once the pony itself was dead first, and he is still alive despite what has been done to him.