Suggested by Destroyer The Destroyed Behemoth is known as the strongest of all Behemoth variations and I’m inclined to believe this as he does look quite fierce. It would be very difficult indeed to actually take him out in a one on one fight. Arch Behemoth would ultimately not be able to keep up here as they have similar abilities so having the better stats guarantees victory. Destroyed Behemoth wins.
Suggested by Destroyer The Destroyed Behemoth is incredibly powerful and not a Kingdom Hearts monster to underestimate. Still, I don’t think his attacks would be able to damage Bahamut enough to really make a difference before he is taken out. Bahamut (SIN) still has the advantage in virtually every combat stat so that’s really hard to try and get around. Bahamut (SIN) wins.