Chijou Saikyou no Otoko Ryuu

Karate fighter Raion Ryu is so unflinchingly powerful that, during a sanctioned match, his strikes accidentally explode his opponent into piles of steaming meat. As punishment he dons a sutra-infused mask to suppress his horrific might and goes into hiding with his psychic sister, but the two are eventually hunted down by his ex-master and the fiancé of the man Ryu killed. While their modus operandi would appear to be revenge, they follow divine instructions from up above—Destroy Ryu before he can awaken as the Antichrist! God himself has put out a hit on our masked hero.