In the world of ninjas, Sai Ueno became an ordinary cannon fodder Chunin, born into a common family, with mediocre chakra and only knowing the basic Transformation Technique.

Faced with the monopoly of ninjutsu, lacking both a ninja clan bloodline and a special ability, in order to survive better in the Second Ninja World War, he could only deconstruct the Transformation Technique using scientific thinking.

While the higher-ups of Konoha were busy harvesting cannon fodder with the Will of Fire, he derived the Beast Mimicry Breathing Technique from the Transformation Technique.

When the genius of the ninja clan was rampaging with their bloodline limits, he extracted the Human Puppet Bloodline Clone from the Shadow Clone Technique.

When the Six Paths' staff clashed with the Flying Thunder God Technique, he derived a quantum teleportation technique that was nearly akin to the Heavenly Hand Power from the Substitution Technique.

...

This book is also titled: "The Survival Counterattack of a Common Ninja," "Beast Mimic Transformation..."