Lore-wise, I don't think Solgaleo even has anything to do with the sun. A bunch of Hawaiians just saw the thing pop out of a wormhole, fight the Tapus, then fuck off a few hours later. It glowed really brightly, so they assumed it had some kind of connection to the sun, like it was gonna eat it or something. In reality, it was just a lion that can shoot light.
