One day peeps in the RWBY verse discovers the ancient cities of the Elder Things, only to discover that they aren't as emtpy as the ones discovered in our worlds. Naturally the Elder Things gets in a conflict with them so they sent out the whole Academy to fight.
The Elder Things have access to most of their stuff and the Shoggoths, althought they are only a single city, not the whole cilivization.
RWBY team is basically everyone associated with the Academy.
No knowledge or prep time, but everyone is still combat-ready. Wins condition is fight until one of the group is no longer a threat. Speed is equalzed.