Kinda need a new mid-late game BBEG

Kinda need a new mid-late game BBEG

Disclaimer about our game: it's a homebrew with very loose rules and highly improvised in the sense that much of the campaign hasn't been planned in advance (some arcs, yes) and is extremely dependent on the choices the PCs make and how those choices inspire me. But most of all playing is an excuse for us, being best friends in our 30s, to find time to hang out more often.

Anyway. Been playing for soon three years. Everyone lvl 12. "Finally" the loose nature of the game came to bite me in the butt and I feel like a BBEG or clear goal is out of sight. The central themes and conflicts are here and the players and I are loving it. This arc has included unsealing gods, changing the past and this altering the present, 'restarting' the story (but also not) in this new present with a few new characters after a few PC's died, and now discovering the eternal cycle between gods and demon lords, and the players are now through a time travel side quest actually about to witness ancient man's ascent into godhood triggered by a Primordial being.

So, a lot of fun, but in all of this I feel like just a classic BBEG has kind of disappeared. The first major villain was a traumatized double agent who during the big war pre-campaign discovered the truth about the sealed gods and set things in motion to unseal gods, and therefore awaken some demon lords. This was all great because the BBEG was for a while, in a way, also empowered by the PCs unsealing gods. However during one of the god's trials they had the chance to right a wrong in the past and basically travelled back in time and changed the past so the BBEG wouldn't begin his evil path.

I'm not really sure where the story will go from here and I feel like at least I need a villain to set things in motion.

There are still a few conflicts in the world regarding whether unsealing gods or keeping them sealed is a good idea or not. Another major city is also plagued and occupied by dark forces after one nation summoned a god at the end of the last war. And the PCs have been hired by a archmage who is using them as guinea pigs with his time travel device.

I feel like the archmage could become a BBEG. Also maybe this primordial being from the past piggy rides back to the future together with the team, or maybe the demon lords and gods are just pissed that the PCs are jumping around in time. Basically I just need someone or something to declare itself a villain and set the stage for the next course of events.

Im really stuck.