Who came first - the Ones or the Force Priestesses?
I was thinking about this question for a long time and couldn't really figure out an answer. BTW, I'm discussing in terms of CANON, not LEGENDS.
The Force Planet is said to be the "birthplace" of the Force - and thus also the birthplace of life. The Force Priestesses is an ancient entity beyond our comprehension (source: Dave Filoni), and "embodied the connection between the living Force present in lifeforms big and small, and the larger, timeless cosmic Force." They were the first to discover the secret to spirit immortality as well.
Then we got Mortis and the Ones. Mortis, by all accounts, seem to be on a different dimension entirely than the known galaxy, and the actions on Mortis are seen throughout the galaxy, and vice versa. The Father is described by Lucas as "the Core of the Force." The Son and The Daughter are the embodies of the Force itself, and unlike the Force Priestesses, have achieved a form of living immortality - not spirit immorality.
If The Ones were the first beings in Star Wars, how could they be the embodiment of the Force before midichlorians were even introduced to the galaxy?
Is it possible that the Force Planet was there grand creation (think Big Bang), and that set everything else in motion?