MTL - Naruto Lineage Theory? Trash - Chapter 724

In this world, orphans or just anyone without any hope for this world can apply to become a “walking target”. Their sole purpose is to be a practicing dummy for the students of the sect who train to become “Demon Hunters”. These students need “walking targets” to test their training on living, walking beings of flesh and blood.
In exchange, they will be provided with food & shelter.
Their existence value is lower than a slave, but if they manage to survive a few years they can receive a life long pension.

Xiao Han is such a “walking target”. One time he witnessed a powerful Demon Hunter disposing a demon. When the demon died, a fragment of the demon that managed to escape entered Xiao Han’s heart. No one saw that, and even Xiao Han himself only felt some discomfort for an instant.

But that thing in his heart soon gave Xiao Han visions, and the first one is of a cultivation method which allows Xiao Han to absorb damage to enhance his body. A perfect cultivation method for a “walking target”.

- Description from Novelupdates

He is a young man without a spirit root. It is believed that this denies him the chance at cultivation. However, a mysterious lady imparts a Supreme Demon Classic to him and from then on, he starts his path of cultivation.
He undergoes a total transformation to emerge as the most fearsome and powerful fiendish demon in his era, that even immortals and fiends are fearful of him, and saints are at his beck and call.
Mastering the Supreme Demon Classic is the turning point in his life. He is able to unleash his immense and divine power from within, illuminating the entire universe!

- Description from Novelupdates

A cultivation technique that is regarded as rubbish, and a cultivator who is regarded as a waste by the same school, after receiving a yin and yang jade pendant, everything will be completely changed.

Ten times the training speed, Gu Fei repeatedly broke through the limits of martial arts. The iron law that had been recognized for thousands of years was broken by Gu Fei one by one!

Miracles… Gu Fei doesn’t believe in miracles. He only believes in blood and sweat. In this martial art has fallen, the true meaning of martial art has been lost in the training world of Tenglong Continent. , Fighting demons and ghosts, embrace stunning beauty, and achieve indestructible Wu Zun!

- Description from MTL

Finding himself in an Last Airbender without an airbender around, a transmigrator waterbender goes on an adventure to stop the worst from happening to him.