Villains' Sisters Yearn for my Copious Mana

"Be wary of skirt storm, my boy," Max's grandpa passed him the golden rule, just like he passed his inheritance and truth about their family's origins.
After learning all of this, Max naturally decided to become like his grandpa. He would visit dungeons and other worlds, then get a ticket to the legendary tower!
But first, he needed a good experience, for he had never had any contact with fantasy worlds. Luckily for him, the villains on Earth had a pretty interesting scheme, which Max would benefit from!