MTL - I Will Be The Crowned King - v4 Chapter 511 only by myself

Mechanics fix things.Fighters break ‘em.Those were the two truths Perry lived back on Earth. When he got isekai’d into a young noble with newfound magical powers, he found himself stuck with an awful choice. Try to survive on the Front, the mystical battleground where Hydras and Devils roamed free… Or find another way.So he took an oath. An oath that made him a Magus Dominus. A mage lord. He’d escaped his fate, least for the moment.For most his life, Perry was used to being alone. When he got sucked into Ro'an, he was suddenly thrust into the role of surrogate son to his loyal servant and half-brother to a tempestuous Storm mage. With their help, Perry prepared his best to be lord and protector for his domain. And if he fought a few monsters, and helped a few people along the way, well…Mechanics fix things. And fighters break ‘em.-Progression Fantasy with light LitRPG elements-No romance-Kingdom building and magic progression

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

She, the tribe leader of the Miaojiang witch tribe, was reborn as a pitiful little girl that everyone could bully.

She – a glutton without troubles or worries who crossed over and became a young fat chick with a deep vengefulness.

He – a young master of the number one power; a two-faced man with elegance and charming, good looks; he is the chosen one of the former saint god and a man who will only bend his back for her alone.

This domineering crossover’s slogan is, ‘Don’t touch if it is this sister’s, put it there even if it isn’t this sister’s!’

…watch how the Domineering Glutton and the Two-Faced Venerate Emperor create sparks as they meet and collide, stirring the whole Spirit Treasure Continent into turmoil, how they fall for each other and how they kill each other, how life and death sever love.