Kapitel 25: Emiya Shirou in the Clocktower (Fate/SN UBW)

The request is this: Shirou's adventures in the Clocktower following the UBW true end, or maybe even the UBW good end, if you wish to do that. Perhaps send him on some mercenary missions or something to hunt down magus who have broken the law of magi. Maybe let him go on some journeys with Lord El-Melloi II/Waver Velvet as well. It'd be interesting how other magus would react to the name of Emiya, and this could all lead into some brief crossover involving Zelretch, though that's not at all necessary if you don't want to do that. If you want to really think out of that box, maybe you can add Fate/Grnad Order events, but I wouldn't recommend it since so much of canon has to be changed. Maybe Zelretch sends Rin and Shirou to an alternate timeline, and that's how that happens? In general, I don't have too many specifications on this one.