I just re-played 5.3 on a new character for the first time since finishing Endwalker on my 'main' and was stunned to see Endwalker's main plot armour .. what I call the "orange crystal of emotional investment killing" .. IS INVALID!
Why?
Because if you watch the post-Seat of Sacrifice cutscene, at the point where Elidibus is kneeling on the ground in white 'Amourtine' form the player drops the 13 crystals they'd collected in the quest "Etched in the Stars" and the orange Azem's Crystal is one of them; unsurprising really given I doubt SE had come up with the "and with one bound they were free" part of Endwalker's climax.
When Elidibus' body evaporates into a cloud of aether so do the crystals INCLUDING AZEM'S.
So Endwalker's end story has the player use an item THEY CAN'T HAVE!
LOL, SE need a story continuity expert methinks.
/sigh