Delock, Portal Assassin

Delock, Portal Assassin costs {x} less to cast, where {x} is the converted mana cost of creatures put into graveyards from play this turn.

First Strike, Infest, Flash, Final Word, Dredge 7.

{t}: Target creature's power or toughness becomes 1 until end of turn.

{u}{u}{u}{x}{ut}: Creatures you control with power X or less are unblockable until end of turn.