>>9276253>>9276278>>9276288>>9276296>>9276287>>9276282>>9276311SP Godzilla is the same Godzilla that came from the bones. It's the same Godzilla seen in the "Koshira" painting. SP Godzilla has been interacting with humanity at various points of its life stages, slowly getting better at manifesting itself. It "died" last time after attacking Ashihara's village due to being incapable of producing enough Archetype to sustain itself as Ultima.
When he finally did show up again, he has far greater control over the Archetype and was now truly assimilating into the human world. You can kill him or send him somewhere else, but he will keep returning as he is a Singular Point, and so will other kaiju. It'll be neat to see him get into a scuffle with a mech made from his own skeleton. The whole series is a prequel to a world where they gotta keep fending them off.