From a chaotic future, Mirai (Future) Trunks comes back in time and kills
Freeza bot, along with his father, King Kold. He warns the Z fighters about his
future, and tells them how they can prevent any of it from happening. In Trunks'
future, two androids, Numbers 17 and 18, are wreaking havoc across the globe.
Surprisingly, he can also become a Super Saiya-jin, making him the second (in
our timeline, that is) to become one. This really pisses Vegeta off, who later finds
out that Trunks is his son. When he goes back to his timeline for the second
time, he finds that history had not changed. But he is a lot stronger so he kills
androids #17, #18, and even Cell.