I've spent SOOOOO much time thinking about One Piece in the last decade, LOL. Also, since I've tried (and am still working on) making my own magic systems in my writing, I've spent a lot of time just analyzing them in general.
It makes sense that Nuclear Force would be able to defeat monsters like the Gorosei, some Godzilla shit. We even Saturn flinch at the sight of the Mother Flame:
Saturn looks like he's terrified of the Mother Flame. This would also explain why real Dragons/Lunarians had to eliminated, as well as Ancient tech: if the lasers Kaido/King shoot, and the lasers the Pacifista shoot, can actually damage the God's Knights/Gorosei, the WG would want to have this tech under lock and key.
My question is this: we've seen Luffy grab lightning.
Luffy: "Are you having fun, yet, Kaido?"
And Kaido did. Kaido had fun.
If Luffy can grab Lightning...
What happens if Luffy grabs a Mother Flame?