I use progenitus in my kaiju deck as my commander, I can get him out pretty quick, but pod usually doesn't like it because the end up board wiping my mutate monsters. But he is fun to play if you can ramp early.
My 5 Color Godzilla deck is in the making right now. The other fill cards will be the Japanese spells from Strixhaven. As well as some Foil cards from the Kamigawa block. The theme will be humans/vehicles and mechs from kamigawa battling with and against the Godzilla cards. I am hoping a lot of stuff from this new kamigawa set will meld well with the godzilla cards. My non basics are going to be altered by myself to put some of the monsters in the background much like the secret lair land drop