Demogorgon's Fury

You evoke the wrath of Demogorgon, the Prince of Demons! You touch one willing creature and their arms turn to tentacles, you are unable to attack with weapons but you can unarmed strike for 3d12+ your strength modifier bludgeoning damage, their speed also becomes 40ft (if not higher already), you also gain immunity to being charmed, frightened and poisoned, if you were charmed, poisoned or frightened before the spell was cast the effect is postponed.