The crafts men and metal were being gathered to unmake all artifacts and magical items
The party encountered Red, an immortal created during the death of twin gods of the sun and mood from a time long forgotten. Red was good but has devolved in to a nihilist.
The hurled themselves back in time creating a world ending paradox in order to collect heroes from across time for the final battle. this rapidly accelerated the coming of the end but the uncontrolled destruction was not what the enemy had in mind. The chaos unsealed was nothing short of Leviathan.