Bio Weapons

You turn one arm of a creature you can see into a large scythe like blade out of their own bone and flesh. It functions like a Simple one handed weapon. That deals 4d4 of slashing damage. You may expend one hit dice to give the arm reach for one attack.

when casting at 4th level 4d4 at 6th level increases to 6d4 at 8th level 7d4