K-2SO

"'There is a 97,6 procent chance of failure.'""-K-2SO to Kassian Andor."

K-2SO was originally intended as a security droid for the empire, but was reprogramed to work for the Alliance. K-2SO was capable of hacking, using weaponry and co-pilot and pilot ships. A very handy droid to have on your side.

K-2SO were joined in a misson to rescue Jyn Erso from the empire, he stopped her when she tried to run from the rebels. K-2 were often on missons with Kassian Andor, they made a good team, and would soon evolve into the "Rogue one" group. K-2 would spend his last days with the crew of Rogue One, trying to get ahold of the Death Star plans.

K-2 offered himself to defend the door to the control tower on Scarif  (were the plans were held), for Jyn and Kassian, so they could get away with the Death Star plans. He defended the door from stormtroopers and beach troopers. But when he knew he wouldn't be able to defend for much longer he smashed the console, blowing himself up, locking the door from the outside. Making the delivery of the plans to the fleet above possible.