Here's something I wouldn't be surprised regardless of the answer to:
Would you recommend one of the Hyper Beams on a Pokemon I would use in the Battle Hall? It packs that big power, and the recharge turn shouldn't matter because they only have one Pokemon, and I would only use it on stuff that:
1. I wouldn't be able to OHKO with any of my other moves, and
2. (i'm most certain) i'll OHKO with it.
The only thing I really have to worry about with Hyper Beam in the Battle Hall is if, god forbid, it doesn't OHKO the foe. And if I knew it wouldn't OHKO, i'd just use another move and do more damage within the two turns. Or maybe i'm missing something here.
In short: Is Hyper Beam usable in the Battle Hall where the foe only has one Pokemon?