Blood Pact

You say a short prayer towards your patron, asking it to embolden your strikes. You take 1d4 psychic damage and until the start of your next turn, whenever you hit with a weapon attack you can add 1d4 psychic damage to the damage dealt. 

This spell's damage and the psychic damage you take changes to 1d6 when you reach 5th level, 1d8 when you reach 11th level, and 1d10 when you reach 17th level.