Yone, The Unforgotten

Sacrifice any number of demons on your board, as an additional cost to put this card on the battlefield.
The power and toughness is the number of demons on your graveyard, at the moment this card enters the field, plus 2.
{b}{b}{t} - Search your library for a demon revel it and place it on your hand.
{r}{r} - Place a seal counter on any demon on the field, that demon has first strike and haste for the rest of the turn.

One to cut, one to seal