I don't know for sure. But Tree of Ruin go ahead and corect me if I'm wrong. But the team that went into the vault was actually written out of time. Basically the weapons are pieces of the team. Now I've also heard (don't remember where) that the relics are either one of the team members. Or that they are defeated gorgons and we're changed into the relics. Not positive. So refer to OP on this but this is the lore I've heard.