Every villain from the beginning of Dragon Ball to the end of Super in a massive rumble. Power levels, speed, durability, and other relevant stats are all equalized. AoE is not (which is to say that Tao Pai Pai's Dodonpa can hurt Cell but can't make a blast the size of a planet). The arena is the same size as the Tournament of Power arena, but also domed with a 100 foot ceiling. Any character who is ten counted in real time gets disqualified.
Scenario 2: As above, but with all non-villainous tournament antagonists who never became main characters (such as Giran or King Chappa) included.