My universe is a fantastical universe, and the area is a Viking area. My three characters are :
- S, a character who was born female but raised to think they are a man to protect them from their father who is obsessed with sons. S is torn apart by their secret, has to live with their awful father and twin brother, and try to protect her younger brothers who are shy and submissive to their father and her twin.
- A, S' first love who is married to their awful brother, mother to his children. They wanted to be married to S but had to marry the first-born but still doesn't know that S was born female and when she learned it, she reacted pretty badly. She can absorb and release strength, pain and injuries to cure or kill someone.
- M, a mermaid who had a crush on S when she saved them from drowning, she is born from a magical spell and can't have biological children in order to avoid creating humans born from magic.
My idea was to separate S and A because A can't understand S' identity, while M is also born with a different identity.
Then A's kids become sick because of a mistake S made, and A absorbs all the energy of M to cure her kids through her magic. It kills M, and S is destroyed by M's death and can't stand seeing her former love and her nephew and niece who are alive because of M's death.
My question is : How can I justify this choice without going for the full "A is an old fashioned lady and M is the modern girl" ? Outside of these events, I want A and M to be close (because yeah M will come back from the dead), M to help A when she's doubting, helping with her kids, A to care for M when S is away. But S still has a choice to make, and I want it to be felt as the logical end of their love story with respect and caring rather than a hateful moment, that M will understand why A made this choice and A to feel that M is the best choice for S.
(Hope it doesn't seems like I am asking for creative ideas like it's forbidden, I really want to improve my style and how I write.)