Wasteland Development Diary - Chapter 20 - Various Knight Orders

When Lin Su discovered he could travel between two different worlds with his tamed beasts, the world gained a Beast Tamer formidable in a way that defied science.-----------------------------------Without a system, without a female lead, Crossing Two Realms, original taming beasts

After waking up in the body of the Young Master of the Luo family, he finds he has the knowledge of hundreds of games and Light Novels. However, he finds his Dantian is crippled, so he can’t practice cultivation! Luckily, he has the Upgrade system.

Back in 1991, in the face of this golden age, Chen Jianghai swears that he will only live in three words in this life: Lin Wanqiu! The story of a reborn person who built an electrical empire and reached the pinnacle of his life!

- Description from novelbuddy

You thought being reincarnated as an extra-side character was bad? Imagine being thrown into the body of a villain who is disowned by his own family and discarded by the author.