Demitri before Pyron and after Belial...It's super close but I think Slayer might take it if he can avoid the Midnight Bliss, which I think he can. It's still kinda confusin' cuz I doubt Slayer can take powered down Pyron, but that would be A>B>C logic.
OG Demitri (100%) or post Pyron, ruins Slayer, tho.