Any Chōsin, and quite easily at that. Not only did Tokimi create ten universes each with increasing complexity versus the Lord of Nightmare's four regular universes*, universes that she want to- but can't destroy unless someone summons her to that universe. The Chōsin on the other hand were clearly quite capable of destroying their own creation.
*Slayers TRY isn't canon and neither is the Knight of the Aqua Lord manga, so it's only four universes like Hajime Kanzaka intended, hence the four ma-ō and the four shinzoku.
Originally posted by BeyonderGod
Lol Chousin got rekt by one person
Note, during the entire fight they were explicitly limiting themselves so as to not destroy the universe (and thus their experiments therein). I.e. within the 3 dimensional universe, they can be contested, but only as long as they limit their abilities to ones that can fit within said universe. If they used their full power, they could win but at cost of the universe.
Basically any one of them simply going to full form is the equivalent of Gigaslaving whereever they are.