Mark

I actually think that it is possible. Gohan is the Z equivalent to Freiza if he would actually take training seriously. Remember during the Goku Black arc, Goku and Vegeta was in and out of that room a couple of times. Gohan jumps levels after a touch of training. He's trained a quarter of the time as Goku and Vegeta. Imagine if he went into the Hyperbolic Time Chamber for 3 days straight lmao

The Buu in Super doesn't even count really, this should be DBZ only. Buuhan was the strongest, then Buutenks, in terms of strength. Kid Buu had the complete absence of malice, and pretty much no soul, so he was outright the most ruthless version. He also boasted SS3 level strength, no stamina loss, and unmatched regeneration. All of that made Kid Buu the most dangerous. He also is most impressive because he will never lose his power naturally.