(Disclaimer: I don't own RWBY or Fallout.) What if Jaune was presumed dead during a mission against a white Fang base, and was transported to the East Coast?

In this timeline, the grimm went extinct after the bombs fell, dust doesn't exist, but Huntsman and Huntresses exist in the world do, where laser rifles were made to cut thru enemy aura and one Huntsman or huntress has to unlock another's aura so that they can start using it or even discover their semblance. Though, at present, there hasnt been a single Huntsman or huntress in 200 years, they are renowned as legends warriors. They are reguarded as such since they held the "lost art of aura" and inhuman abilities as wastelanders put it. But what does that have to do with you? You are the Baddest motherfucker made by the fires of the Fuel war. Huntsman and Black Op Soldier. Your uncle Robert House and Grandpa Dr. Mobius gave you items to prepare for the bombs to drop. 200 years later, you and your girlfriends survived in refuge of Vault 111. But when a merc named Kellogg has taken your son, you, Nora, Winter, Wiess and your new friends of the Commonwealth come together to kick some Wasteland ass. From helping poor souls, aiding synths, becoming a B.O.S. Paladin and General of the Minutemen, to slaying abomintaions of the Commonwealth. Watch out Institute, you just pissed off a legendary Huntsman.

❝ Watching her with the Big Daddy, it was suddenly so clear. It wouldn't stop, it would never leave her. It would never hurt her or shout at her or get drunk and hit her or say it was too busy to spend time with her. And it would die to protect her. Of all the powerful men in Rapture over the years, this thing, this freak of science, was the only thing that measured up in an insane world, it was the sanest choice. ❞