HAHAHAHA mothra destroyed a planet busting meteorite with no problem
and Godzilla tanked a city busting nuke and did not even flinch, the only reason Godzilla loses to mothra is she usually gets help,
not to mention one of his cells flew into space, flew into a black hole, came out a white hole, and was bombarded by super novas and was completely un-harmed, all that did was made it stronger and formed space Godzilla (who has that much power)
if u want to talk planet busting i know a few kaiju that are easily planet busting, in the Godzilla universe
not to mention burning Godzilla
and if u want i can put a non-canon form of the franchise super Godzilla
cthulhu is about a grand king ghidorah level, or mabye even less