Rebirth: Necromancer's Ascenscion - Chapter 62: Forked Tongues and Silver Knives

It begins on the mountain.

With the glint of a knife, a flash of steel in the hands of a sworn brother. A betrayal.

Stabbed and pushed down the mountain, Zi Chen lied within the red-stained snow, left to die.

This is where it begins; he is given life by lightning,
baptized by thunder.

Those who had once betrayed him should all suffer in his cruel revenge.

- Description from Novelupdates

The person that Pei Zhen hates most in his life is the perfect Fu Sichen. Alas, life is full of surprises and unpredictability. One fine day, an accident turns Pei Zhen into Fu Sichen’s pet cat! As Fu Sichen’s pet cat, he makes a shocking discovery about his sworn enemy – a deep dark secret that the perfect Fu Sichen has kept hidden for years. Trapped in his cat body, Pei Zhen moves from one adventure into another while trying hard to find a way of turning back into his human self. When he finally does, the world as he once knew, has become a completely different place!

In 1930s Canada, a 16-year-old landlord unlocks a System unlike anything this world has seen—a power that lets him grant supernatural abilities drawn from warriors of another realm. Barbarians, Archers, Wizards… all under his command.

An ordinary sect cultivator, with the help of the immortal mansion, gradually grew up in the cruel world of immortality, and his mind and body transformed together.

Mortal flow, partial dark wind.

- Description from novelbuddy