What if My Brother is Too Good? - Chapter 32

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

After transcending to a new world, Ye Xuan miraculously obtained the Swallowing System.

Not only could it swallow everything (wink wink nudge nudge), it could also extract bloodlines, martial arts, godly weapons, medicinal pills, treasures…

“This (beer) is way too strong! Don’t challenge me! Do you believe that I can’t swallow your divine swords?”

- Description from Novelupdates

Zheng Tan somehow returns to the year 2003, turning into a black cat. Picked up from a rubbish heap by the Jiao family, he is given the name “Charcoal”, and so begins the life inside Professor Jiao’s family. Zheng Tan remembers that he was once a person, but currently his body is that of a cat. He has no way of speaking the human language, but can understand it, and even retains the thinking and IQ of a young 20 year old youth. Read along as he adapts to this new world, and somehow tumbles from a group brawl to catching a thief.

- Description from Novelupdates

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.