You draw blood from yourself, forming it into a powerful slash. Choose a number of hit points to sacrifice: 1d8 or 2d8, and reduce your current hit points by that amount. Then, make a melee spell attack against a creature you can see within 10 feet of you. On a hit, the target takes slashing damage equal to 4d8, plus a number of extra d8s equal to the same amount you rolled when sacrificing hit points for this spell. Also on a hit, you can push the target away from you, up to 10 feet for each extra d8 you rolled. The self-inflicted hit point reduction induced by this spell does not count as damage or affect your concentration.