An Immortal Courier?

A person who died to a prototype satellite beam ends up meeting a god who gave him immortality and a system that has infinite space for inventory along with a survival oriented type system now is in a world that has now become a nuclear wasteland but has at least 5 months tops before it happens and was given a temp card with infinite money on it.

However this universe is not ready for a man who has meticulously remembered every single device blueprint in his old world and now is bringing them with him and because of his system it also let's him see his memory's to understand what he'll make, and thats even better.

And our hero has one dream and that to create an independent faction, screw the enclave, screw the legion , screw house, screw yes man , screw BOS and most of all screw THE NCR!

Wait hold up the god is saying something....

WHAT HE CAN BRING MODS TO THAT UNIVERSE TOO!?!?