Torgaar, Famine Incarnate

As an additional cost to cast this spell, you may sacrifice any number of creatures. This spell costs {2} less to cast for each creature sacrificed this way. When Torgaar enters, up to one target player's life total becomes half their starting life total, rounded down.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6omavwg8p1pb1h40qlcadu.