Xianxia: Why am I here? - Chapter 13

Crossing to One Piece world, he became Roger’s younger brother.

Unexpectedly, Gol-D-Roger who was in his fifties had a teenage brother. But he was so weak.

Fortunately, at the age of sixteen, he actually found himself with a possession soul system.

He had attached to the master IP man, also to the White Phoenix and to Ge Nie with his strong ability of the Hundred Step Flying Sword.

If you think that he can only Purchase these? Then you’re wrong!

Pain, Itachi, Ichigo Kurosaki, as long as there is money, any soul can be Purchased.

- Description from Novelupdates

In the grand weekend year, demons cause chaos, and people cannot live peacefully.Han Zheng, carrying the game setting he designed [Taotie Furnace], travels to this world. By sacrificing to the furnace, one can break through martial arts techniques.From [White Ape Extended Arm Fist] to [Ape Demon Nine Transformations].From [Vajra Fist] to [Great Vajra Ming King Seal] and then to [Great Mighty Dragon Bodhisattva View].From [True Martial Refinement] to [True Martial Holy Body] and then to [True Martial Indestructible Body]There are no gods in the world, hence demons run rampant, and evil spirits are everywhere.As Han Zheng kills his way through the chaotic world of demons, looking back, he has become the only true god in this world!

Being taken away of all his freedom, Noah was thrown into the jail accused of a murder he hadn't committed.

This incident broke his personality permanently, getting out of the jail Noah started living as a shut-in giving up at everything.

Noah read novels as a mean to pass his time, while reading novels an particular novel caught his eyes, it's name was 'the hero of velveric fights the demon lord'

'It's a harem novel......'

That was what Noah had thought in the beginning but, it all changed at the end of the novel.

'What the Hell's with this crazy novel!'

The protagonist and all his harem members were killed and in the end the demon Lord took over the world.

It was then, after finishing reading the novel, Noah started coughing out blood and succumbed to his lung disease.

Opening his eyes Noah found himself in a body of a 8 year old kid of the Melvix family which appeared in that crazy novel.

He was known as the garbage of the Melvix family by all the knights and family members but that didn't matter to Noah. What matter is that-

'It's impossible to survive in the novel if you are not strong enough......'

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