Actually speaking of copying memories reminds me of what happened with G'raha and the scions on the First. When we took the scions and popped them in crystals their visible selves on the First vanished (as their bodies were just aether I think?). But when G'raha copied his soul? memories? into the crystal he still had a physical body on the First, fully functional and with memories etc. So was the real G'raha (that we'd dealt with all through Shadowbringers) the one who died when he turned to crystal, and was the copy of his memories in the blood-crystal vial simply a copy like the Endless? Which we then merged with his our timeline version on the source. So is G'raha essentially like a half Endless because he was copied? But we're sad at the First G'raha dying (does that mean that G'raha went to the aetherial sea on the First and our current one will go to the aetherial sea on the source?), and treat the copied G'raha as if it is him.

It seems a little similar to Otis having his robot version and Endless version as he has a copy yet also still has the original running around and active.