Mysterious monsters without much explanation?

[RyuDragnier]

We still don't know where Ultima came from beyond that Ajora called her from another realm. Is she a space alien like Omega and Midgardsormr? Is she something summoned from one of the shards? Somewhere else beyond the rift?

My personal headcanon is that Ultima's a shard of the Ascian Altima who went out of control, and the WoL of that time was the one who sealed her away originally.