One day in Flameclan camp, a grey she-cat with white spots named Mosslight gave birth to two small kits, a black and white tom named Fallenkit and a silver tabby she-cat named Featherkit.
Their father was Flamestar himself. One day, when they were 10 days old they met their father for their first time. Both Featherkit and Fallenkit were excited to meet their father/leader.
When Flamestar came to the nursery, he grunted and looked at the kits with disapproval. He told Mosslight, that he has disappointed him with these kits, especially Fallenkit because he had only one eye.
When it was time for them to become warriors, Flamestar made Fallenpaw a medicine cat app, saying that he wont be a useful warrior.
Fallenpaw was shocked that his father hated him so much and was even more shocked when Flamestar took a new mate, Silvertail, who had 2 tom kits named Flintkit and Redkit.
Fallenpaw sadly became a full medicine cat and got the name Fallenwish while Featherpaw became a full warrior and the name Featherspirit.
Fallenwish was sick of this and got a plan. He decided that he would poison Flamestar's prey with Death Berries but it backfired and Mosslight ate it, and died.
Fallenwish was shocked and ran away and left the clan and his sister behind.
(And if your are curious, Flintkit and Flint the leader of Snapclan are the same cat but that is a different story)
But I remember the backstory for him