Need help finding a manga/manhwa
Guy activates some power through princesses. He competes against the dwarves by building a steam engine, and that wrecks the enemy who are using blocky tanks.
He also shows off a ballpoint pen to the dwarves. Dwarf princess wears a veil and he saw her without it, complicating things.
I think he unlocks power by kissing princesses? I don't recall.
Thank you.