Maybe Sakuya Izayoi? 

From a touhou perspective, perhaps Alice and Patchouli could come to Marisa's house to demand their things back. Depending on who wins, a witch or a pair of witches gets tied up over the cauldron. 

For Fate, you can try to do a train robbery? Even if you don't have a train interior, use some large crate props with perhaps medicine on them, next to the train you used in a previous KC DiD. Given the America chapter had some desert segments, it could be supplies meant for spells or machine soldiers. You could guard it with characters from that chapter like Nightingale, Billy the Kid, Helena Blavatsky, Rama (Mobile)/Sita(Arcade), Nero Bride, etc.