I really like the movie and thought it was a lot of fun but there were a few things I wish they had done differently or included.
There’s a big exposition dump in the middle of the flick, which a chuckled at because Dr. Andrews is supposed to be reading pictographs yet she’s telling the story like she’s just reading sentences. Anyway they give you all this info but still never tell you where the hell the Scar King got his magic crystal that controls Shimo. That’s kind of a huge plot point that’s never explained.
And holy crap has Godzilla’s atomic breath just become way too OP. You already know how all of his fights are going to end.
I thought it was clearly a dead Zilla spine carrying energy, which by now we know he could recharge within Hollow Earth. The only question now is why it could subdue and order Shimu around, is it a Titan hierarchy thing, are Shimu and Zilla related, or are Godzilla's powers becoming magic now?