Voldaren Bloodcaster // Bloodbat Summoner 298/277

Oracle text

Flying Whenever this creature or another nontoken creature you control dies, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.") Whenever you create a Blood token, if you control five or more Blood tokens, transform this creature. Flying At the beginning of combat on your turn, up to one target Blood token you control becomes a 2/2 black Bat creature with flying and haste in addition to its other types.