His mother hates him for unknown reasons, hersecond litter is Copperkit, Whorlkit, Sedgekit and Kinkkit. The two boys die first, the next two die too. They die in leaf-bare by freezing to death. Pikejaw is good father and likes him. Songstream says that all her kits are dead, ignoring her last litter. Rainpaw tells this to his siblings when he goes back to the apprentice's den. Cedarpaw (Cedarsnow) yells at him that she didn't say that (even though she did, like really dude if you didn't want to get killed you could've just believed him). The day Sedgekit and Kinkkit die he is taken to the dark forest in his dreams, and is taught that he should kill Songstream and Cedarpaw to teach them the "right ways" by Ashstar (one of my bad boy leaders who like is a jerk. I don't feel like explaining that right now). After he becomes a warrior, he takes Cedarsnow (who also became a warrior with Sunnyleaf and Pineheart) to the river in their territory to tell him something "important". When they get there, Cedarsnow is knocked into the water by Rainfern who hit him in the chest, and is now bleeding and flailing in the water. He hits his head on a sharp rock and Rainfern washes his fur off, then leaves. He says that he slipped into the river but he thrashed too far away from him to help the tom without drowning too. As they mourn him, Rainfern joins them to make it seem like he really did slip into the river. He fake cries.
At least three years later, two clans (DarkClan and LeafClan, Rainfern lives in LeafClan) clash for territory. In the fight, Songstream joins them though she is an elder. You can't make her leave, the leader tried. During the jumble of cats, Rainfern manages to kill Songstream. She stares at him in horror as he tears into her chest. With all the scents and the amount of blood around, they couldn't tell who killed her. A few other cats are killed (not by Rainfern).
At the end of his life, ten years old, killed four cats (the other two were just from different clans, though he meant to it wasn't that important. One day he is hunting and an eagle is going after the mouse he is too. Rainfern pounces on it and kills it, and the eagle swoops him up after taking it's meal. Its talons dig into him and made him bleed to death in the air before he is eaten.
Long live my mistreated murderer.