The power of the Super Dragon Balls was stated to be unlimited. ANY wish. I'm hoping (if Frieza gets the wish) he will use it to rewind time to before he went to Namek, so he can obliterate Goku with his Golden Form, resetting Dragon Ball similar to Steel Ball Run from JoJo. Then it's up to Future Trunks to round up the past Earth's greatest heroes that survived both the Saiyans and Namek in order to defeat Frieza, claim the Dragon Balls, and fix history. May be a good point to introduce the Supreme Kai of Time into the show as well.
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And by Earth's greatest heroes, I mean Yajirobe, Chi-Chi, Puar, Oolong, Master Roshi, and maybe even have him hunt down Gero and release the androids (who aren't as powerful because Gero hasn't perfected them yet or something) and Mr. Satan, of course. This time, actually training to become the hero he pretends to be.