One of Dragon Ball Z's most popular characters is Future Trunks, the sword-wielding half-Saiyan warrior from a much darker timeline. Introduced into the series by taking out one of its most fearsome villains, Future Trunks and the Terminator-like world he came from were both a part of one of the franchise's longest and most well-received sagas.
Dragon Ball Super brought Future Trunks back, and finally explained why the Z Fighters of his era were never revived. In a darkly humorous twist, it turns out that none other than Emperor Pilaf's gang, a trio of villains from the original Dragon Ball, were the reasons why history's strongest warriors never returned to Future Trunks' timeline.
The Androids Ruined Future Trunks' Time
The world that Future Trunks came from was one in which many of the Z Fighters had been dead for years. This happened after Goku's died, not in battle but instead from a mysterious heart disease. With their de facto leader and strongest warrior gone, the Z Fighters were unable to defeat the eventual onslaught of the Androids, who were created by and led by surviving Red Ribbon Army member Dr. Gero.
Trunks travels to the past to keep this future from happening again, even if it doesn't fix his own timeline. This begins with making sure that Goku doesn't die, but Trunks also sticks around when the threat of the Androids surfaces in this timeline, as well. After the Androids and Cell are defeated, Trunks goes back to his own time to take them out there. He makes quick work of Androids 17 and 18 thanks to his increased power from when they had last met. With their defeat, Trunks soon does the same to his timeline's Cell, bringing seeming peace to the Earth. Unfortunately, the question of why he didn't try to wish the Z Fighters back was still unanswered, especially given the presence of his mother and the Dragon Radar.
Emperor Pilaf's Last Wish Defeated the Z Fighters For Good
The story of what happened to the Future Timeline Dragon Balls is revealed toward the end of Volume 2 of the Dragon Ball Super manga. Emperor Pilaf and his gang, Shu and Mai, sought out the Dragon Balls after the Androids first attacked. They gathered them and wished for their youth to be restored, only for Shenron to it take too literally and make them infants.
This ridiculous transformation would sadly be the last wish that Future Shenron would ever grant, as the timeline's equivalent of Piccolo would die soon afterward. This turned the Dragon Balls into mere stones, and with no one knowing how to get to New Namek and bring in Dende, it was impossible to use their Dragon Balls to revive Piccolo, Goku or the others.
Ironically, Mai, now the same age as the baby Future Trunks, would give the boy a strange look before he and his mother Bulma departed. Years later, the two would become incredibly close as their Earth's defenders, with many believing that the young warrior and the former villain were in love and simply afraid to admit it. Emperor Pilaf's wish is also a sort of the reverse of Episode 1 of the now non-canon Dragon Ball GT, where he wished for Goku to become a child again. While this situation was humorous and fitting for the over-the-top Dragon Ball villain, it ended up spelling absolute doom for Future Trunks' world. In this way, Emperor Pilaf inadvertently caused more damage and destruction here than he ever did in other storylines.