Naruto: Reborn as Orochimaru - Chapter 360

Luis, a poor 17-year-old boy, tries his luck at becoming an Awakener to change his fate. However, his dreams are shattered when he fails to awaken a Special Spirit and is instead saddled with a 5 million dollar debt by their planet's colonizers, the Flying Star Empire.His life seemed doomed—until a mysterious system suddenly appeared in his head: The Monster Transformation System. It gave him the power to transform into any monster or animal he had ever seen.From a cat to an eagle, even a horse, Luis begins to understand that his power may not come from Spirit... but from the ability to become any monster.

Matthew grew up in a decent family filled up with hopes, dreams and big heart, but living a shitty life which were suddenly demised with the unexpected turn with a mishap. With the new changes of his body, he finds new powers and wondering into new dimensions. This new enigmatic power is suddenly taking soul form his body and making him something beyond of his imaginations.... His tasks are unclear but he has to take soul of each demon he meets in his path... With his powers he has bigger responsibilities in each of the dimension which is beyond explanation…

On a certain day, Xu Xing suddenly received yin-yuan eyes; he could see a red string between lovers. Then he discovered that he had a tight connection to his own left hand.

Xu Xing: I TM …… will I be ‘solo’ for life? : )

The second day.

Xu Xing suspected that he had seen a pair of ‘gay’s. The left side of the boy’s body had two red strings. The one in front was tied to his hand, the one in the back was tied to the boy’s right side.

The bottom of Xu Xing’s body suddenly tightened. Trembling in fear, he turned his head — only to see his ‘local area’ connected to a red string tied into a beautiful, intimate bow that was attached to the school grass sitting behind him ~

Xu Xing: Excuse me???

- Description from Novelupdates

A man who was once called the world’s strongest agent ended up becoming a teacher after his retirement, to train a new generation of agents. After many years of training his disciples, he was killed at the age of 60 by a secret organization’s ruse and was reincarnated in another world with his memories intact. Though he was surprised by the existence of magic and the strange species in that world, he quickly adapted to his condition as a newborn and took advantage of it. He acquired special magic and gained a massive amount of strength thanks to his rigorous discipline, in order to reach his goal: Resume his career as a teacher which he left halfway through in his previous life. This is the story of a man, who, based on the memories and the experiences of his previous life, became a teacher who travels through the world with his students.