Tsuki ga Michibiku Isekai Douchuu - Prologue 3: Goddess=Bug

Upon being reborn, she immediately offends a vicious two-faced bigwig.

Chen Mu, a low-level officer, thought he could only live a cautious life, but unexpectedly he got a system panel that could accumulate experience, and he could master all the skills with just one practice.

[Blast Knife + Gale Knife + Wind Chasing Knife = Blast Artistic Concept]

[Jade skin grinding method + sand iron method + coarse salt method = skin of copper and steel]

A peerless martial saint with unparalleled swordsmanship, bronze skin and iron bones, and a body of pure gold was born step by step.

- Description from novelbuddy

Nagasawa crossed to Naruto Universe and was bound to Konohagakure.If Konoha is severely damaged and destroyed, Nagasawa’s lifespan will be reduced.He panicked at the thought of the upcoming Nine-Tailed Demon Fox's attack , and the thought of Konoha getting destroyed left him in despair.Fortunately, while bound to Konoha, he can obtain templates of powerful characters.At the beginning, He got the Whitebeard template! Since it's the Whitebeard from the Summit War of Marineford, he can use Tremor-Tremor Fruit's ability and Haki.Facing the Tailed Beast Ball, which terrorized Konoha Shinobi, Nagasawa leaped and shattered the Tailed Beast Ball with one punch!

It’s a story about a man who got transported into a novel and possessed a slum boy. He met a noble girl and served her as a butler for 13 Years. Now the girl has already fallen from her noble life and lives in an abandoned mansion with paralyzed legs. Why did she become like that? Of course because she is the villainess in the novel.