After the attack on the village Charles Lee takes Connor with him to whatever mansion he lives in and keeps him as his (sex) slave for years on end. Cue timeskip and now Connor is a young man, completely broken and following Charles' every command.

For some reason Connor ends up with Haytham - maybe Charles grew tired of him and decided to gift a well-trained sex-slave to his best friend, maybe Haytham visited Charles, saw the slave and liked him so much Charles gave Connor to him, maybe something else.

Either way, Connor ends up with Haytham, who is most pleased with him - the young man is very submissive, polite, eager to please in any way possible.

Only later does Haytham find out the truth about Connor's identity.

Bonus points if he still keeps him as his pet but treats him with utmost kindness and Connor because painfully attached to this new, gentle master.