User blog comment:SuperNerd295/KAIJU DEATH BATTLES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 3/@comment-24277243-20150731202106

Gigan wins. Megalon had trouble with Jet Jaguar of all things, and he relies on a group of people to tell him what to do. The moment he loses contact with the Seatopians, he goes crazy.

Gigan, despite also requiring guidance, appears to be the most competent Showa kaiju in my opinion. Sure, when he lost contact with the Space Nebula M he started to lose the fight against Godzilla and Anguirus, but at least he didn't go crazy.