Naruto: The Unstoppable Saiyan

He acquires the methods for cultivating ki from Dragon Ball and masters every technique he can think of: Tri-Beam, Destructo Disc, Solar Flare, Instant Transmission... You name it, he figures it out.

His name alone strikes terror into the Shinobi World. Anyone who encounters Ito Hanei is permitted to abandon their mission without penalty. Successfully escaping him even earns a reward.

"We finally got away! Hahaha! The Land of Water is just ahead! We can go home!"

"Yo... You guys are dreaming if you think you're getting away."

"Y-you! When did you get here?! It's at least a ten-day journey from where you were!"

"My Instant Transmission isn't just for show."

"Aaaaaah!"

Whoosh! Just like that, he's back at the Konoha camp. Job done.

"Sensei, I want to learn Instant Transmission!"

"A dead-last like you wants to learn Space-Time Ninjutsu? Dream on."

"You jerk! You're dead-last yourself!"

"All right, settle down, both of you. If you want to learn, go train hard. Run five hundred laps around Konoha."

"Sensei, what's your dream?"

"To protect the village and everyone in it..."

Note: Sorry, this isn't a harem-conquest story.