The pumped-up popadanets / The Conquest of Issekaev (Konosuba)

What will happen to the various stories if the place of the insecure OYASHA is taken by a man who has dreamed of power and a personal harem all his life? This is a story about a man who got a chance for a second life, and then for a third, fourth, fifth… And he will stop only when there are no undefeated demon kings and girls forgotten by the Oyash in the multiverse.