So, he's not, um... human? While I can buy having Divine Spirits, I think they should at least
look human in order to be summoned. Summoning a literal giant snake is pretty outlandish and not at all the kind of thing the Holy Grail War is about. I'd make him a man with rainbow colored hair and maybe scales on his arms and legs or something.
Other then that, the sheet is pretty good. As I said before, Australian mythical figures are quite rare to see around here, much less gods (other then Crow), and you conveyed the sense of grandeur and scale involved with the Dream-Time nicely (mind you, some of these myths literally date back to
before recorded history).
I really like his first NP. It's exactly the kind of esoteric conceptual stuff that attracted me to
Fate early on (along with the chance to see mythical heroes beating the crap out of each other, of course
). I can only say that, given the sheer scope and diversity of its effects (particularly the Third Magic bit), I don't think an EX rank would be inappropriate.