RPG makes maths lectures far more fun.

I'm guessing we'll face/meet a/several robot(s) based on the area so
1. The Gaul Pit - Asterix & Obelix - hopefully still the good guys.
2. Castle Bleck - Count Bleck + whatever mario themed creations you can come up with.
3. Osthreinsburg Arena - filled with Soul Calibur bad guys, not fun.
4. The Elsinore Yard - Hamlet (more widely, Shakespeare) so King Leer, Macduff.
5. Angband Battlefield - Middle Earth according to my friend, hence, Ancalagon - even less fun.
6. DeGroot Keep - TF2 can only end hilariously.

Gaul Pit sounds least death filled, I vote there.