Actual answer:
We can't know, unless the Gods tell us directly. Syncretizing identities is something only Clergy can truly do, with the rare exception of a member receiving some info that is relevant to their journey/nationality/so on, in which case 95% of the time, the Gods will tell you to not spread the info willy-nilly anyway.
Speculative answer:
He seems to be a chthonic aspect of Father Zeus, similar to Hades, in the sense of being seen as a highest deity, but with a darker aspect.
He does, however, seem to have some elements that connect Him to Lord Ares.
I don't really know enough to speculate deeper, and just going off and reading to give a rushed response here doesn't seem like the tactful thing to do.