Defiler of Flesh

Menace As an additional cost to cast black permanent spells, you may pay 2 life. Those spells cost {B} less to cast if you paid life this way. This effect reduces only the amount of black mana you pay. Whenever you cast a black permanent spell, target creature you control gets +1/+1 and gains menace until end of turn.

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o72xy48s7pb1hksjd3dq1.