Some time ago, I made Fallout Equestria Oc's cause… I was bored. Winter and Pepper here were my first.
Pepper and winter are twin zonys, born from a Enclave soldier and a zebra prisoner. Due to their less than desirable conception, they were abandoned by their birth mother and raised in an orphanage. While they were constantly bullied by others, only Pepper retaliated, preferring to prove her strength by beating the shit out of those who bothered her and her brother. Winter rarely fought back so Pepper came to be very protective of him. Due to being one of the few unicorns in the enclave, Winter often felt isolated from the other foals and ponys who lived in the clouds. Because of this, Pepper chose to almost never fly, wanting to remain on the same surface as her beloved brother.
After many years of training and hard work, both Peppermint and Wintermint became soldiers, though Peppermint was stuck being just a private. While her skills were enough to make her an officer, her violent and impulsive nature made it impossible to trust her enough to lead any group. That and she only really listened to Winter. She followed orders but she only worked well with her brother.
Peppermint is a harsh, prejudice (She hates everyone except her brother) and violent. Shes the type to choose a fight over rest, food or companionship. The only one in her heart is her brother since they only ever had each other. She would do anything for him, which she later does when Winter goes Dashite.
Winter is a cold and calculated, though he is just as violent as his sister. The only difference is that he's much better at hiding it. The main difference between the two is that Winter actually cares about other ponies and the surface. He wanted to help ponies. He loves his sister but he has a much bigger heart than her. He later leaves the Enclave for the surface to help the surface dwellers.