As much as I'd hate for them to sloppily shove whoever in as if they were an afterthought and then put Omega as the final boss, this is also a likely option to happen. This has been a survival tournament of sorts so you'd be fighting the final contenders that have made it this far and then deal with Omega itself. It could be more than just one of the games in there. It could be something like 7, 8, 9 and then Omega at the end.