Reborn in the 80s, Get Rich by Eating Melons - Chapter 637: Found the Dog

Ethan transmigrated from earth to a post apocalyptic martial world with a system.His system has only one function: Double the attribute every day. Watch him rising in the universe with a pace faster than the speed of light.

Turns out your childhood best friend — the one you always thought was a dude — was a babe all along....And she has WHAT? A Yuri harem? (An all-girls harem? Seriously?)While she attracts women as easily as breathing, women run away from you the moment you breathe?

In a world where human and monsters relied on mystical fruits and their inner power to fight for dominance, a lost soul was thrown, given the powers from all the other worlds he’s known. But there was a catch; he had no control over what power he would get! With knowledge beyond that of most, he sails his path to the top of the one piece world!

- Description from Novelupdates

Yang Feng somehow transmigrated into a different world and received a legacy of an ‘ancient high tech’ family, which does not directly raise his power, but gives him the technology to build things which are way more advanced than the seemingly medieval world.