[EDIT]: I had all the pieces i needed, but the other 2 players said that I wan't able to insta kill anything. can someone explain how this combo works?
February 10, 2017 5:59 p.m.
Necrotic Ooze's ability allows it to have the activated abilities of all cards on your graveyard, in this case that means the relevant abilities:
Exile top card of your library and add +1/+1 counters based on exiled card's CMC to Ooze. (From Devourer)
Remove a +1/+1 counter from Ooze and deal 1 damage to target player or creature. (From Ballista)
Pay and add a +1/+1 counter to Ooze. (From Ballista)
Basically as long as there is no response from your opponents, this allows you to exile cards from your library and ping down player's point by point. You might also see this done with Triskelion in place of Ballista.