I'm not sure???? Honestly, I though he was the son that Lucas rejected to take in as a student, while saying "I won't teach this good for nothing" Or smth similar.
I am not sure the story change different in light novel.
In my opinion. This not anastachius, this carax or illegitimate child from first emperor (he really fans lucas) but he can't be king cause he didn't have strong magic like everyblood noble king (he meet lucas when the first emperor introduce him), lucas really don't like him cause he mixed ( I think he make a black magic and become magician so he can long life like lucas).
lucas mention previously (i can’t find the ep) that he refused to teach someone else before he teached athy and it was hinted that the person was anastacius. that’s the only relationship i see between the characters
yes I believe he was the son he rejected
https://who-made-me-a-princess.fandom.com/wiki/Aeternitas_de_Alger_Obelia
Someone please correct me if I’m wrong, isn’t Anastacius (?) the guy who Lucas is/was said to be closed to?? Like, in the early part of the story, there was an emperor Lucas was friends with. ALSO, MY HEART IS WEEPING!!! DID YOU SEE THE CREDIT PART?! WHY CAN’T WE HAVE A WHOLE FAMILY T^T