>>125104542- The stone mural in the human castle suggests that specifically humans and deertaur united the worlds, and I'd guess Nowhere King's from that deertaur family (if not the one depicted)
- The beartaur's table (at the start of his song) has a centaur on the minotaur's side, implying either a defector or a spy.
- The minotaurs knelt down to Nowhere King when he passed
- We have "centaurworld" and "human world" but no minotaur world, suggesting they might be exiled or invaded rather than just the aggressors
I'd guess he was a centaur who defected, possibly for good reasons (e.g. believed it was an unjust war), but still understood why the Woman is angry and would let her kill him.
His theme definitely seems to be a corrupted lullaby, too, implying he learnt the original version as a child or as a father.