MTL - Anti-Cheater Strategies - Chapter 15 Teacher and student shackles (fifteen)

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

When The Cute Kunoichis Spied on Their Teacher's Secret is a light novel written by Kazuma Kamachi and illustrated by Ryuushi Tajima.

The story takes place in a world where Japan never ended their isolationist phase, and agents from foreign powers are always threatening to steal the country's advanced technology. In order to combat this threat there has been a resurgence of ninjas that use Strategic Martial Arts, techniques that combine cutting-edge modern technology with a traditional foundation of martial arts and ninjutsu. The story follows Souha Sugiyado, a 17-year old ninja instructor and former ninja prodigy who was forced to retire from active duty by the wounds he suffered in his last mission. Souha's four students are all kunoichi who have all gained the rank of Elite Ninja, the highest official rank available to ninja. However, one day two Shogunate ninja approach him with the news that his four students have gone rogue and have stolen a portable modular nuclear reactor, and thus they ask for his help in bringing his students to justice.

After being reincarnated in a world called Neron, and destined to be an Average Joe, a common D-Rank Adventurer.

Tyler quickly learns the cruelty of life, after being used as a pawn in a selfish and ruthless war, he ended up being captured by the very thing he was fighting against, demons, without any hesitation he was bombarded along with the demons.

Caught in the destruction of the demon king, he was unable to save himself and fell to his death.

Fate, however, had other ideas, it wasn't done with him yet. After being reawakened in a new era, in the center of the demon territory, he finds himself caught in a rapidly growing and dangerous situation.

Swept in his newfound strength, and caught in the greed of his formal self. What will he do next?

Will he return to the people who used and betrayed him, will join the enemy against the human race, or will he forge a new path.

In the myriad realms, legends rise and fall in the countless eras.