Blue Saint
Member
For me it is just one of those cases where the derivative is a closer parallel than the original. Like how despite being based off of or at the least drawing influence from Superman there are cases where a character or reference is closer to Captain Marvel than Superman, even discounting the Billy Baston angle.I'm pretty sure the Mega-Smasher from Guyver is a gimmick exactly lifted from one of the 70s Super Robots that was desperate to have a novel variation on Mazinger's Breast Fire.
(And if the Mega-Smasher doesn't remind you at least a little of Breast Fire, I'm... just going to assume you've never seen Mazinger.)