[Maybe he should leave these explanations to Ryu after all. They're awkward.] Ah. A god exists not on the physical plane, for our natural world is elsewhere--we must be summoned by mortals to their world. This is the case of all the Endless in the mortal world. Yet, in our summoning ritual, a mistake was made, and where once was a single god were two, for our original self was cleft in twain.
Sentience first, and now Acumen, refuse to allow our reunion. Perhaps it is easier to keep two shards of a god than one full god? [Manageable, bite-sized dragon-pieces.]