What kind of personality does he have? what reason does he have for being here? what USE would he be to the group? we have plenty of people who can hurl bullets down the way.
What do his perks have to do with him? My character has animal friend because she refined her medical skills on animals, so she came to understand how they think and has developed a natural animal magnetism, then I made up my own perk because she's from the Pitt, so she's naturally more resistant to radiation and disease. I understand that him being a super mutant makes stuff like that a lot more difficult, as he doesn't know anything about his life before becoming a mutant, but there's nearly 125 years there that he COULD remember, and you could do so much with it.
You need to give more personality to your character... bring your character to LIFE, not just make it some cookie cutter "Oh hey it's a super mutant.... and he can fix stuff!" we already have a super mutant that can fix stuff, and he has the added entertainment of schizophrenia that leads him to making cool shit which gives him a good approach to just about anything.
Have you given thought to making a ghoul or human instead...? it might be easier to come up with an interesting backstory for them than it would be a super mutant.
I'm sorry if I'm sounding like a bitch, but this is a high casual roleplay, which requires at the very least some character building, and if the character is nothing but a few lines of text, that's next to impossible to do