The spinoffs and Dragon Ball Fan Art questions are asked based on scenarios that we will probably never see in anime canon. They are not completely ruled out, since the very development of the series has shown us how villains end up being part of the Z Warriors.
The most emblematic cases are those of Piccolo and Vegeta. In the last arc of Dragon Ball, the namek was one of the worst villains that Goku could have. And not to mention the serious threat that the prince of the Saiyans came to represent in his first appearance.
Then there are other cases like Android 18 who ended up marrying Krillin and Android 17 and Frieza fighting for Universe 7 in the Dragon Ball Super Tournament of Force. But despite all these situations, something we have never seen is a fight between villains.
Imagine the scenario: two antagonists fighting for a territory or to conquer a planet. And that in addition, these two evil ones are the most dangerous that the Z Warriors have come to face, as they were at the time Frieza and Cell.
The brutal battle between Frieza and Cell
Cell in his perfect form is a warrior who could keep increasing his powers, since he has the Saiyan DNA. While Frieza, with arduous training, is capable of reaching amazing levels capable of fighting against Ultra Instinct or Ultra Ego. That was already demonstrated in the most recent Dragon Ball Super manga.
Who would win between the two? It is complex to know, but this FanArts, identified in social networks as Andrew Gongimagines them in a kind of perfect shot as they both beat each other up.