But you're not talking about this in relation to Erenville. You're talking in circles around a tangent about the value of non-human lives versus human lives without a single mention of Erenville in your previous three responses. There's plenty to criticize about the use of the characters, but going off on this tangent isn't productive to the discussion about the usage of the characters in the expansion. You are expositing for the sake of expositing while derailing the thread with your constant talk about the Endless.
I too was disappointed in the lack of screentime Krile and Erenville got despite all the marketing centered around them and I don't think he was inherently more or less successful of a character than Krile or Wuk Lamat. I also would have liked more scenes between WoL and Krile or WoL and Erenville without Wuk Lamat present. Not because I dislike Wuk Lamat, far from it, but because I think there's a lot that could've been explored. Krile faced feelings of ineptitude despite her accomplishments and talents because she couldn't keep up with the other Scions as a combatant and in one instance was captured and used to empower both Zenos and Krile. The story could have easily spent some time exploring how Krile is dealing with these feelings while wanting to know more about the secrets Galuf kept and never had the time to reveal to her. We could have easily checked in on her because she is definitely brave but has not seen the same kinds of combat the rest of the Scions have. She could've had a reaction similar to Alphinaud's by Gorgagne's Mills where he killed a bear for the first time and had to come to grips with him taking a life in the face of his pacifistic upbringing. She could have expressed exhiliration or horror while wondering about how her experiences compared to her father's.
As for Erenville, I liked the story's portrayal of his fraught, but still loving relationship with his mother. There is clearly distance between them despite still loving one another, what with Cahciua's insistence on using his birth name and Erenville referring to her repeatedly as his "mentor" rather than his "mother". Him clamming up and bottling up his feelings when he learned about Cahciua's death and conversion into one of the Endless was compelling for me since I had a similar reaction when I learned about a family member's terminal cancer diagnosis. I would've liked to learn more about them too, especially since Cahciua apparently wasn't privy to Gulool Ja Ja's and Galuf's discovery of the gate to Living Memory. But I also would've liked more unpacking of his past in Tural and how he and Wuk Lamat met too. They have a vitriolic best friends relationship and I do think he serves as a good foil to him. But a little more character conflict between them about her choices could have been neat.