Board Thread:General Discussion/@comment-31338621-20170223022025/@comment-25449165-20170325001317

BrainBrand wrote: I don't think Heathcliff could take on 9 unique skill users with just what he's shown (if we exclude overassist mode and his abilities as admin). My theory is that his unique skill is much stronger then it appears, having many more abilities then what was shown. Just the most basic skill (his blinding light skill) could be extremely deadly when used, assuming he's not affected by it. I figure he must have some overpowered abilities, including plenty of AOE, or crowd control abilities.

Again, with overpowered abilities like what BrainBrand was saying, it would be cheating. But there is TONS of speculation to go around because Reki Kawahara (or the anime) has never fully explained all the capabilities of Holy Sword, as much as he did with Dual Blades.