I'm getting a very Elder Gods vs Great Old Ones vibe here

From the Celestial Realms coming up against the Void.

Both groups of beings are absolutely, incomprehensibly inhuman. Both groups are beyond our normal reckoning of reality and follow ineffable motivations. And chances are, neither of them care one iota about individual mortals. If their interactions with people happen to end well for said people, then that's simply a side effect of carrying out their agenda rather than a goal.

I think it would be wise not to be quick to assume the Celestials are on anyone's side but their own.

Really, though, this recently released Lore is finally giving some inklings of context regarding the Void and the Celestial Realm. Good show, Riot.