I personally love the idea of...

Age of Abundance (Miquella and Malenia ending) Replace the Order with Blood and Rot. Abundance and decay, probably very utopianistic where everyone may flourish... May or may not have creepy undertones, alien biology stuff like annihilation movie.. something akin to green ending in mass effect 3

Lord of the All-Devouring (Rykard's ending, let's devouhh the world togethaa, maybe you, Rykard, Tanith ascended and become an outer god being that can invade other planets.. but maybe it's greater good...)

Age of Syncretism (Power to the People ending, I intend this for Godrick. Empyrean system and godhood get deleted, but unlike Ranni or Goldmask. The power is shattered and distributed to everyone in the world, everyone will have a bit of power, can commune to multiple gods, etc. but the downside is that set up for a fairly chaotic world where war and strife might become common)

Since Elden Ring endings are pretty morally grey... I don't want to add "good endings", but rather something that you can endlessly debate for their philosophical implications and will measure up to Ranni's ending.

And the Demigods I chose are based on Demigods that are somewhat hinted with the possibility of resurrection... As they don't vanish when we defeat them.