Due to this, Krillin went through intense training to prepare for the upcoming battle but secretly felt afraid of facing the androids.
Three years prior to this meeting, all the Z Fighters were visited by Future Trunks, who told them that 17 and 18 would appear and cause massive havoc around the world that would result in the death of all the Z Fighters and a third of the world population.
Gero was defeated by the Z Fighters and he desperately released 17 and 18 as a way to kill the Z Fighters but the two androids instead betrayed Dr.
