Suggested by Sonic Heathcliff is a pretty powerful fighters and gave Kirito one of the lad’s toughest fights in the whole series. Cthulhu has a lot of raw power, but he isn’t fast enough to hope to do any real damage to Heathcliff. Moreover, Heathcliff’s shield will allow him to block any of Cthulhu’s attacks with ease. Lets face it, this giant monster isn’t really a match for such an esteemed swordsman. Speed wins battles. Heathcliff wins.