Konoha Canglong

Traveling through Konoha, the unlucky Sai Mu Shun, who had very poor talent in ninjutsu, awakened his immortal body. He became a disciple of Might Dai and began to practice extremely strict physical skills.

Matt Day: "If you're not good enough, then work harder!"

Qi Mushun's body was covered in blood. "Is trying until death enough?"

Konoha Whirlwind, Instant Body Technique, Night Phoenix, Lotus Flower, Konoha Dragon God...

Qi Mushun: "No way, no way, there won't be anyone who really uses the Eight Gates Ninjutsu. Will their body be unable to withstand it?"

…

During the Fourth Shinobi World War.

With all eight gates open, Saiki Shun kicked Uchiha Madara in Six Paths Mode to pieces.

Madara boasted, "I recognize you. In terms of physical skills, no one I've fought against is better than you. I, Madara, would like to call you the strongest. This is my thank you gift. Before you turn into ashes, I will kill you..."

Qi Mushun kicked out again!

"Ashes...what is that?"

…

The passion of youth will never go out!

I am the Immortal Blue Dragon of Konoha!

ps: He didn't die in his previous life, his soul traveled through time, and his physical abilities came from the power of the soul's rules (setting, for those who argue, please take a detour)