If it ISN'T SpaceGodzilla, then Gigan seems like the most obvious answer for those reasons. Frankly I wouldn't be upset with either, but Gigan is undeniably cool and probably my favorite Toho villain!

Exactly! They've also been pretty open about this being his first hunt and him being quite a bit younger than the seasoned veteran hunters we've seen in past movies. It'd almost be weird if he DIDN'T look way different.

That's a really interesting thought, especially since Harry already seems to be the preferred choice of both Bella and Conrad. There definitely is some long-simmering tension brewing there, Eddie being Harry's son could break it all open.