On Newgrounds, you're not allowed to be a proxy for ANYONE, regardless of whether it's your friend, your brother, your uncle or whatever. If you make an account, the songs you upload are YOURS AND YOURS ALONE.
So if Stefan Carllson is your uncle for certain, he'd make an account for himself. And I don't think he'd appreciate you doing what you do now. It'd be a tad more embarrassing if we contacted him right now, and he should ever say to us that he never authorised uploads to Newgrounds anyway.
WahyaRanger2
Lol