the cats are goldspark (yellow) shimmertail (grey) and crystalpelt (blue). So basically, they are siblings and their parents are from two enemy clans, riverclan and thunderclan. Goldspark is taken to thunderclan while her siblings are left in riverclan. Many moons later an actual war happens between the clans and goldspark forgot about her siblings completely so in the battle she kills shimmertail and crystalpelt tries to tell her he’s her sibling but she is about to kill him so he kills her first.
Literally almost none of my ocs have backstories where they didn’t kill anyone or anyone they know got killed or they got killed I’m tired bruh