K so this one will take some explaining, and I doubt it'll make sense to many people.

So eclipses backstory is somewhat straightforward, right? Her ancestors, a long time ago, defeated Hoopa and sacrificed themselves to save Lunala from death. That's the story Eclipse knows, anyway.

But there's a second part to that. Solgaleo was there as well. He wasn't fatally injured, though Hoopa had captured him either way. So along with the ancestors of Eclipse, came the ancestors of Solar. That's how they defeated Hoopa. Solars ancestors sacrificed themselves as well, using their own life energy to fuel the heal Pulse. But they had a child, and, like eclipse's great grandmother, Solars great greandfather was blessed by solgaleo. His blessing included a mega form appearance change, a permanent mental link between him and solgaleo, and he is strengthened during the day (though the night weakens him).

Anyways, this is what his mega form looks like.

I know it's garbage. It barely looks different. So sorry for that. I'm not a professional or anything.
RiskTheRiolu 54IgnoredCryst54 Pika-Tails Blitzen233