These droids were sent by Lord of the Stars to Kharl who asked for them in order to help out with his planned assassination of Mandalore. To test them out they were sent on three minor covert missions without any backup against chat forces. Once raiding an outpost, destroying a communications tower, and obtaining a data from a chat base escaping and bringing the data back to Kharl. After succeeding three times Kharl agreed to take bring use them during the assassination attempt of Mandalore .
Y7-37 prefers to use a needler rifle as his primary weapon and dual wielded kig-yar knives as his secondary. Y7-38 prefers to use carbine as his primary weapon and dual wielded needlers as his secondary for close combat. Y7-37 is 6'4 and Y7-38 is 6'3. Both cyborgs are extremely athletic and have even better endurance then the average kig-yar. These kig-yar cyborgs also have the advantage of not feeling pain. They also are a bit more resilient then average kig-yar able to take 3-5 shots before going down unless shot by a explosive and can take two direct beam rifle shots.