Collected Relics from All Realms

Some regrets are so heavy that they can condense into a world. The people who couldn't be saved, the words that were too late to say, the homes that were not kept despite all the efforts - they will not disappear, they will just change places and continue to hurt. He walked into these worlds and became a "scavenger": for the people inside, he settled the regrets that he could not let go one by one. Some are waiting for a word of forgiveness, some are missing the last step, and some are unable to go home until they die. He took care of them one by one. Only the one he was carrying was the heaviest and could never be picked up. He picks up things for all the world, but cannot pick up his own. He only recognized one sentence - it's my fault.