Let me use an analogy from the cosmology of Pathfinder, and particularly the interactions between Pharasma and Groetus, because that is basically the drama you are laying it.
Pharasma has no origin, she constantly moves from universe to universe. When one universe is eaten by Groetus, she moves to the next universe. Whenever somebody asks where did Pharasma come from or originate, the answer is always that she came from the previous universe. There is a kind of irrationality about that answer, it does not follow standard logic same as the Abrahamic god. This is because logic entails that there must be a beginning.
Eventhough the pattern is that Groetus eats the universe, Pharasma escapes to the next universe and begins her recursive irrational creation and recreation and judgement again, my pov is that there is a possibility of error within this pattern. Or, variables may interact with one another in unpredictable ways. Maybe there is a very small chance of error, but remember that we are iterating forever so even that small chance of error is guaranteed to happen if you iterate enough.
The error may be realized in different ways. The obvious possibility is that Groetus manages to devour Pharasma before she is able to escape into the next universe. The less obvious possibility is that Groetus never descends to devour the universe, and Urgathoa manages to transform everyone into the undead so that Pharasma no longer has any reign because she cannot recycle the souls, and maybe she is never allowed to escape to the next universe because her recursive escaping is tied up with Groetus's recursive devouring. If Groetus cannot devour, then Pharasma cannot escape.
You may argue that in the latter situation where Groetus never descends and Pharasma never escapes, there is still time. But, I'd ask there is time according to whom? The undead cannot experience time, and if there is nobody there to experience time does time really exist?