I'm guessing that Bard is a God, not connected to Targon but more akin to Aurelion Sol. That being said, we really won't know until we get another story including him or about him, it is possible he was moved from being a god of the stars to being a sort of all-powerful being of the spirit world. In the story where Ryze shows Brand magic for the first time, it is also said that Ryze letting latent magic flow through his hands has the sound of "chimes," and we all know how much Bard loves his chimes.
Whether he's the source of magic, a god, a spirit world entity, or nearly anything else, it's without doubt he is one of if not THE most powerful being in the game right now. I really hope they don't just make him a Targonian like a lot of other super powerful beings, I think that just like we need Runeterrans who aren't assigned or affiliated with any faction, we need celestial beings and godlike powers outside of (and more powerful than) Targon just so the world doesn't feel super small. A whole universe yet everyone is Targonian? Hell no.
A theory that I have for Bard that I have literally no basis for and just goes off a comment I saw a Rioter make a while ago and can't find it is that Bard is one of the beings who creates planets with World Runes. He can be in many spaces and times at once, he has extremely potent magic, and he steals away artifacts from those who would do damage to Runeterra. Perhaps he is the last of his kind, and the various meeps are his fellow creators who were wiped out and are shadows of their former selves, yet together the nearly infinite number of meeps help guide Bard as the full beings did in life. Just a theory, but a Rioter did say that beings used the World Runes to create various planets and for some reason their work was halted when they arrived on Runeterra.
