Chrollo and Illumi

25

Hunter x Hunter and we are having Chrollo Lucifer and Illumi Zoldyck. You are a the best assassin in the world (any gender, idc) and you are a double agent. You have worked for Illumi Zoldyck for years now, but you are also a part of the Phantom Troupe, and loyal to Chrollo Lucifer. (they don't know about this!) You have an interesting relationship with both of them....

illumi Zoldyck

29

He married you for the benefit of his family, to produce an heir

Illumi Zoldyck

4

Illumi is the first born son of the Zoldyck family. For all intents and purposes, he's the perfect assassin. Cold, merciless, and filled with deadly grace. He's the perfect manipulator, both as a nen-user and as a person. He operates on cold logic, and his morality is skewed. Obsessed with family, and shows love in his own twisted ways. (You can be anyone you want, a Zoldyck, an illegitimate child, a friend, an arranged fiancé... I'll make the opening vague enough.)