Thanks for the responses.
@ Mesa- all of my dmg is with voids. Drain life is merely the finishing blow or useful CC. I'd definitely add the extra drains and mantle if possible, but didn't want this getting too big.
@ srm - I can agree with the nightmares- I might keep 1- its main goal was so I could use up all my DL's as CC if needed. Stilettos are indeed for reflective/emerald shield. I'm kind of iffy on how to keep deck size down, though.
@ idle- SoV is traditionally very slow- the devourers help keep your opponent from out-rushing you. Late game they help power the drain lifes, if there are any left. I can see your criticism of the nightmare, but I'm not sure why you're against the stiletto- it doesn't really detract from the deck, its cheap, and it provides a small boost in healing/backup KO. More Mantle is probably good, more DL is good, SoV- Read the OP..
This also wasn't really made to counter anything, and firestall would be a terrible matchup. Firestall rips this apart- sanctuary > devourers, reflective shield > drain life, deflagration > SoV
I'll edit the OP with a new build later.