Naruto: I Can Only Use Sage Techniques

Feng Yao accidentally transmigrated to the Hokage world. With mediocre talent, he spent ten years learning only four E-rank ninjutsu. At last, during his graduation exam, he obtained a "powerful" System and mastered every form of senjutsu.

"Ding! System bound. The Host can only use senjutsu for the next six months."

Feng Yao: "Kakashi, still trying to steal the bells? Sage Art: Wood Release: True Several Thousand Hands!"

Kakashi: "You're going to kill me over some bells?"

"The six months are up. The Host can now only use Medical Ninjutsu."

Feng Yao: "What the heck? I'm about to fight Madara right now. You're not kidding, are you?"

Madara: "Of all the medical ninjas I've ever seen, no one comes close to you. I, Madara, declare you the strongest!"