
Spoiler:
From what I saw from another website I usually read at, Idel was the first person to love Liena in the original timeline before Liena comes back in time, apparently she was supposed to be the beloved daughter of the Cassius family and was supposed to be adopted instead of Liena (hence why the ex husband couldn't bring himself to do anything romantic with her because unconsciously he remembers her as his sister in a way), when they were at the orphanange until the end Idel was the first person who loved Liena before she even got her power to manipulate minds and make everyone love her, in Liena's eyes Idel is the only person capable of loving and that's why she finds it hard to believe she dislikes her in this life, at least that's what I understood from spoilers I have read previously, hope this helps
I'm very very curious on why Liena is very possessive about Idel? Can someone tell me the spoilers?