When you are done with the Black Ring the game will be over. If you still have a save before hitting the gong to start the blessing ceremony, you can reload that, pick up loot and finish any remaining quests before continuing (though you would have to redo some stuff).


There is no way in the game itself to return to Rivellon from the wastelands, but you can hex teleport back to pick up stuff (not sure if you will be able to complete any previous quests, though).

Teleporting Anywhere, via hex editor


The technique in the following topic may also work (ie replace the data file, reload the game, pick up stuff, save, restore the original file, and reload that new save).

FIX for the Missing Catacombs Portal