Dragon Ball Kai

Android #16 decides to enter the fight in order to prevent Cell from reaching his Perfect Form, because Cell's goal is not to kill Goku, but to destroy life. The two fight at an even level, with #16 landing a massive blast on Cell. However, Cell survives and uses the opportunity to absorb Android #17. Cell transforms into his Semi-Perfect Form and gains incredible power, after which #16's attacks prove utterly ineffective. Just when all hope is lost, Tien appears and uses his Tri-Beam technique to hold off Cell so Android #18 can escape.