I Have a Versatile System

Mocked by his mother-in-law, he unexpectedly obtains an all-purpose errand-running System. Run errands for people across myriad worlds, and he can earn all kinds of rewards: martial arts, medical skills, wealth, and more.

He first acquires the Great Shift of the Universe and the Dog-Beating Staff Technique, boosting his strength. Then he learns a complete martial arts system and begins to make a name for himself, crushing bullies, taking down spoiled rich kids, and ultimately rising from a nobody to a winner.