Superb choice! XAOS from Greek mythology could be another potential example of such.
Other figures throughout Greek mythology could work here, too, depending on how you wanted to order a particular universe. They were rather fond of the personification of abstract principles, really. Chaos is the main one, but the Theogony also has a few more, like Eros and Eris. I'd have to dig out my copy to get the full list though. There's a whole handful of them that spawn from Chaos.
So where's Entropy on the scale? Were any of our First Ones actually Relationals or Fundamentals?