Sagenose. One of his kits, Snipkit, drowned, his mate Birdwing and his kit Fidgetpaw were stolen by Twolegs, and his last remaining kit, Curlypaw, left and became a kittypet. He lost his entire family.
Mapleshade. After her Clan found out her kits' father was not Birchface, but her mate Appledusk, her leader cast her out. Her kits ended up drowning in the river, and her mate and his Clan rejected her. But she did become a murderous, insane cat, so I didn't feel as bad for her.
Spottedleaf. She was killed by Clawface, and every day she had to watch Firestar become closer and closer to Sandstorm, and farther and farther from her, and then, right before he went to StarClan, she was killed by Mapleshade while saving Sandstorm , sacrificing herself to save his mate, so they were never together in StarClan.
Bramblestar. Everyone distrusted him and Tawnypelt because they were Tigerstar's kits, and he had to prove himself over and over again. Even then, cats distrusted him. But now, all of his cats respect him and trust him.
That's about all. As always, fellow warriors, I will see you later!