Hey there. As you can see, I've been a bit of a lurker.
Did some research and noticed there's no saves out there with all the relics within them, or said they did and were flat out lies. So I've decided to manually edit a save to have all Relics.
I've taken my time and made this save (and Gamertag) for those to be able to get a hold of all of them.
Just load up the save and Gamertag onto any device (make sure to reassign the save to the Gamertag), load up the game, pick Rex, and drop whatever relics you would like to your main Save/Gamertag.
It's an offline Gamertag I just made today so you don't need to be online or off to use this. I hope you guys enjoy.
All Relics Save.7z