I'm surprised Heisei Goji didn't get saddened at how he can't move as fast as Monsterverse Godzilla. I'm assuming you are gonna have them react to Godzilla icing Ghidorah. Er...well...Frying. Depending on if this is Heisei after his death then I'd argue he would be more surprised by Legendary being able to survive the Burning State & turn it off. Heisei Burning was...well I would say cataclysmic but that's honestly understating it. If he wasn't blasted by freezing weapons, at the end, he would have taken the entire world with him. I also love how you acknowledge how chill Heisei Ghidorah is compared to the other Ghidorahs. Makes sense when you consider his origins.
Fun fact:i thought rick said "Oh yeah sure lets bring him in for appear" but when i watched the movie with caption’s,i realized he said "Oh yeah sure lets bring him for a beer."
ik this is an au but for some people that think mothra and battra are friendly with eachother, it's not rlly like that. They just teamed up to beat godzilla. They used to actually battle a lot back in the past