>>38391101Gen 5 attempts to replicate or reimagine gen 1, it makes sense that they would go back to their roots by ripping off kaijus. Haxorus has very obvious kaiju influence so its not much of a stretch to assume Volcarona and Haxorus to be part of this.
But it's not even any of them but Bisharp who is the most telling evidence. It's very obviously an homage to Ultraman(the guy who beats up kaijus from the show gamefreak went on record saying pokemon was inspired by)