>>281403618
Imagine being one of those absolutely broken heroes and being able to return with not only your powers but also an inventory full of mana-producing fauna. You could introduce mana to Earth and unlike the isekai world you wouldn't have to worry about Gods or the planet summoning equally powerful entities to stop you. Just imagine, if you had enough tamed monsters to summon you could have them breed into an army and even experiment on hybridisation with humans if you wanted to. You could wipe out entire races and replace them with your beautiful otherworldly subjects. You could feed your family members elixirs, adjust their bodies into something superior through magic and metamorphosis, essentially creating a new superior ruling class consisting of your loved ones. Imagine the undead armies you could raise, or the hordes of goblins and orcs you could release into other nations, not only would it be a clean way of eradicating humans without doing too much damage to the environment but it'd be hilarious to watch the carnage it produces. Everything that makes this world insufferable or irritating to live in could be eradicated with your own hand. Those you hate could be truly and utterly removed without having to compromise, and naturally if you wished to torture and humiliate those people you'd be more than free to do so. Just think, everything that exists would be free for you to colonise, the universe would be your sandbox, and with an appropriate mastery of time and space you could introduce all kinds of beautiful and intelligent lifeforms to repopulate the universe after you've purged it of filth!