>>53653834You know how the bike lizard powers up the first time you find it and feed it a sandwich?
And how it pops out of its pokeball when Arven mentions he's gonna make sandwiches?
I think this implies that 'raidon wasn't actually hungry. The sandwich just reminded it of the comfort of home, cause Arven was forced to take care of it when he was younger. He probably fed it sandwiches, so feeding him one gave it the comfort it needed at the moment to temporarily overcome its trauma and transform into its true form.
Arven is very tsun towards the bike lizard, but deep down he cares. Also, I think that the bike lizard likes Arven, because he probably gave more attention to it than the professor did back then.