As almost everyone in my group are Dr Who junkies I felt obligated to have Christmas oneoff in my Kerberos game. (Yes Doctor Who has appeared as an NPC from time to time) So I went with MaOCT. I rebuilt the PCs as weird children. The knife happy teleporting thief became a slightly insubstancial, quantum skipping little girl with razor sharp insults. The quasi Batman/Iron man ended up becoming Stewie, large head and all. The metal maniputating blacksmith who can summon metal armor ended up with metallic scales for skin and having to hide in a Kenny-esque parka.
The city's population was transforme into children when a bad guy trickes Maeve (Kerberos NPC) into wishing the world was more child like. The now pint sized heroes must battle their way through the streets of London to London Tower to prevent the resurrection of Mary Queen of Scots.
One player rolled quad tens on Face+PuttDown on a looter in a bakery literally calling him "Fatty-fat-fat-fat" and made the kid weep. A second player kicked a teenaged Beef-Eater in the nads and gave him an 'atomic wedgy.' A third player put the partially resurrected Marry Queen of Scots in a head lock and popped her head off like a Crystal cork.
And then they all made snow angels at the end.