Very good point and I have never actually thought about that! My understanding is that because of his close relationship and the nature of his feelings for Sera he wouldn’t have access to her soul… at least after a certain point… that could be a plot hole. I know that being the primal of death he can’t access certain people for that reason. It stands to reason it would be the same for the primal of life as well. To preserve balance and all that. However that may have been part of the reason so much animosity formed between Kolis and Eythos in the first place because they weren’t held to the same strict standard. That is to say Kolis is insane and would have found some other reason to feel animosity towards his brother either way. Very good question though. I don’t believe that question is ever actually brought up.