Alright, since we are going right past protagonists and on to cosmic entities, let's start with the deity who shares my user name: Zagaroth.
Er, long story short: shared roots to a D&D character I made in the 80s, and was my first username in 1995. Anyway, on to the present...
In his current iteration, Zagaroth is the primary creator deity of my universe. This is not the first universe he has participated in creating, but it is the first one where he was the instigator, and the lesson he learned from those previous ones was to get good help. So he carefully recruited other gods from other realities, formed a plan, and then entered the eternal chaos void of nothingness that ever waits outside of any reality.
And there he dwelled, ignoring that which wanted to unmake him until he found the right fluctuation in the endless froth of non-existence. This he claimed, amplified, and built upon, blooming forth a new infinity and universe. This was the moment that he sent the call to his allies, who joined him in forging the nature and details of this reality.
By the standards of anything remotely mortal, his power is effectively infinite. But the reality is "nigh infinite", for it is infinite in some measures, but not all measures. He is the divinity least likely to act directly, if simply because it is incredibly difficult to reduce his power sufficiently. If he must act upon a world, he will generally form an avatar to contain a fragment of himself and that avatar will in turn use magic to create a remote simulacrum to act through.
Just don't mess with time in his universe. Aside from multiple timelines creating issues with the multiplication of souls in the afterlife, which is not affected by the flow of time in the same way as the mortal world, Zagaroth is too integral to the universe for him to be divided. Instead, he would have more copies of the mortal realms to be aware of and keep track of. Technically, it makes him more powerful, but it's not enough so to be worth the headache.
However, he is technically only the second most powerful divinity present. But the other's power is diffuse, and only a small portion of it is in this reality.
Li, the shattered one, who has no idea what he is.
Li, the rat-were hafling child who accidentally was at the epicenter of a universe's destruction, and became the conduit for all of that power. He should have died along with everything else. Instead, he became the unwitting creator of an entire multiverse.
At the very beginning of the first age of creation Zagaroth invited a shard of the eternal child to join him at his new home, where Li and one of Zagaroth's avatars spend an endless afternoon together telling stories and enjoying a seemingly small meal that always had more food. This was enough for what Zagaroth needed, and he was happy to spend the time talking with his strange friend.
Li does not, cannot, understand what he is. But one of the things he is, is an incredible subtle force of benign chaos. Simply having one of his shards present at the creation of all things in Zagaroth's universe added to that new existence. This was the final secret to creating a universe with such infinite potential: there is always the possibility for something new and unexpected.
Now some portion of Li's shards exist inside of Zagaroth's universe as well as in Li's multiverse, but Li's shards were never entirely isolated to that multiverse anyway, nor are his shards always the same. A ratling, a were-rat, a street urchin with vaguely rat like features, it's all the same, and they can be found anywhere. The perpetual pre-teen doesn't understand himself or reality well enough to be limited by any preconceived notions, so these shards are not limited by the same things others are limited by.
He could be in any and all universes. Including the ones you create. And the one we live in. We'd never know.
Then again, in a way, neither would he.
Then he becomes the pillar of the whole series.
