(I accidentally deleted my post so I had to repost and rewrite everything again, so I added a few little extras)
Arnyek usually calls Lumino and her descendants endearments, only call their full names when she’s serious or they really pissed her, and then something bad will likely happen to them.
Arnyek usually calls other ancestors by their names. Although she doesn’t see them as close as Lumino, she still pretends to treat them as part of the family. She enjoys being respected and seen as a leader.
Lumino calls people by their names, almost never uses endearments except when something wrong with him like when he is saying goodbye and he plans to never see you again. Only times he called Arnyek “sister” was during the Great War and by their final encounter before he committed