my madoka magica au for arc v version 1.

 Yuya is a magi who uses swords his soul gem is his pendulum and his wish was to fix all magical people (cuss Yuya's a boy and a magical girls for me are either gender so I call them magical people or magi) so when Yuya enters a winches labyrinth and can find to body of the magical person get the grief seed he can restore that person to before the made a deal with Kyubey.

 He made a contract with a different Kyubey that has emotion and lives with him although Yuya can if he fall into despair turn into a witch as any magi but on the other hand Zuzu can restore witches into magi if she can make them sensible again by finding there soul. Both of them are a lot older than they look there about as old as the Kyubey have been around maybe a few hundred years  younger.

Version 2

Yuya and Riley are the magi in this one Yuya is hated by Declan and all the others after they learned he had killed people (witches) before but hold no hate towards Riley even though she did help him and has taken some down on her one. Riley and Yuya live together a few miles outside of Miami their territory.

version 3

Yuya can dive into witches to fight there soul and restore it back to it's body but to do this he has to leave his body leaving it defenseless to the witch. But Yuya has three brother Yuto, Yuri, and Yugo they protect his body either by fighting the witch while not injuring it too much because this would also hurt the magi who became it but they don't do this one very often they usually play keep away with Yuya's body by throwing it around.

version 4

Yuya is the only magi in Miami his brother's having died not turned into witches he carries their broken soul gems around with him hunting witches. But sometimes his brother's spirits can help him out via taking over his body.