Dragon Ball - Zeroverse (Doujinshi)

Years after Goku first meets Uub, he is pleased with his student’s growing strength and takes him to the next Tenkaichi Budokai to test his progress. But a threat from another universe is moving behind the scenes. A mysterious adversary from Universe 0 seeks to return to Goku’s universe and needs the Dragon Balls to do so. The adversary revives Babidi, who awakens the remnants of Majin Buu within Uub and makes him a puppet. Goku and his allies must stop the enemy from crossing into their universe.