Sun is very charming and sweet (but sometimes hysterical). He likes to try different kinds of rocks as he journeys with Moon. Though he doesn't naturally have the ability to shape-shift, the magic pearl gifted to him from Moon allows him to.
Sun was taken from his nest as an egg by a party of monster hunters. They had been paid to do so by some Dark lord or whatever, for some immortality spell or something.
Stealing a Sunstone Golem's egg is no easy feat. First you would have to climb up a super tall mountain. Then you'd have to try and take one from a colony (which is hard to do so without dieing.) And then if you managed to do that, you'd have to transport it very carefully back down the mountain.
Anyway, the monster hunters gave the egg to some of the Dark lords servants and got a big buck for it. But on the way to give the egg to the Dark lord, it hatched. Though a baby sunstone golem was still valuable, it wouldn't work for the spell. It required a pristine egg, with no cracks and definitely not hatched.
The servants needed another egg, but decided to take Sun to one of their secret hide outs where they keep beasts and monsters locked up so the Dark lord can use them if he pleases. While Sun was there he met Moon and they both escaped together, as even though Sun was just a baby, he was quite strong and capable. Moon, even though he wasn't much older, promised to try and take Sun back to his mountainous home. After a long trek of avoiding humans, the two reached the town at the foot of Sun's home. But they also made a terrible discovery. A mysterious being, going by the name Eclipse, and one of the Dark lord's servants, went up the mountain and killed all the golems and stole their eggs.
Having no home to go back to now, Sun decided to travel with Moon. The two new found companions stayed together ever since. And both promised to get revenge on the Dark lord for what he had done.
