Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 8 - 8-10. To the Duke's Castle

When gods gather, lightning will strike and the earth will move. Immortals! Which of the numerous way to immortality should one follow? Immortals are hard to seek, but why should immortals hide? Heaven has no mercy, but humans have emotions, and these emotions hinder the road to longevity!

Train the inner self to stay calm, train the external body to be resistant, then cross the three continents and four seas alone, and fight valiantly with demons and devils! With the heavenly baton in hand, raid the devils and demons without any resistance! Take one step to cross nine stars and chase the sword in the dreams! Traverse a thousand li of river and mountains in a single day! The exceptional beings do not mix with the ordinary! Within the universe, where can one find an obstacle! Moving like a dragon, with talent like a phoenix! The heavenly Daos and stars will guide one’s way!

- Description from Novelupdates

After Xia Feng transmigrated, his heart was mysteriously removed.In its place, a defective demon heart capable of sustaining life only for eighteen years was implanted.This is a magical heart that can sync with the power level of its target.To stay alive, he bound himself to the ultimate villain of the future, a Destructive Witch who was destined to destroy the world.The stronger the Destructive Witch becomes, the stronger he becomes!Thus, Xia Feng realized, it's not my fault for stirring up trouble: “Miss Witch, I admit you're strong, but not strong enough!”

One day a young man found a mysterious door in his grand father house and that door transported him to Tensura....welcome to the new world...all the credit for the characters and main story goes to the owners, this is just a fanfic none of the characters or the storyline belongs to me...Tensura won't be live until later in the chapters, so if you in a rush, you can quick rocks...

Ye Yang, the son of the Ye Family in Eight Desolate City, was once regarded as a genius. He could awaken his Dantian at the age of three and reach the third level of Qi Condensation at the age of five. But after a few years, He was seen as a person without talent because his cultivation was still stagnant at the age of 16. One day, He was framed and kept in a coma after he was rescued.

Ye Yang was originally an instructor in a special troop. He was 21 years old and sacrificed his life to protect an unknown broken sword which was found on Everest. When he woke up, he became Ye Yang from the Eight Desolate City, unexpectedly obtained the recognition of the broken sword and learned the mysterious cultivation method “God Slaughtering Technique”. He then embarked on a path of cultivating through slaughter.

When he was reborn, he swore, “I won’t let those who offended me off.” He wanted to reach the peak step by step, and also carried the mission to uncover the secret behind the Nine Heavens Mysterious Sword.

- Description from Novelupdates