Shinwa Densetsu no Eiyuu no Isekaitan - Volume 2, Chapter 1 – The Great Imperial Capital Part 2

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 sky thunders, Fang Yue, the nail household, dies on the street, the heavenly court blackmails, obtains compensation, reincarnates, and sees how Fang Da Devil disturbs the universe and upset the world.

- Description from MTL

To take a dragon's hoard is to challenge death.The greatest of the sea-drakes wakes, curled on his silver throne; but there is no silver. His hoard is stolen. He rises, screaming, and chases the thief to the ends of the world—only to be shot from the sky.But dragons do not die easy, and never one with such festering hatred. A dungeon core rises from his corpse.If he intends to survive so near the cove of pirates that slew his past self, he'll need to master his powers—and quickly. For these pirates are dragonslayers; they won't be felled by mere mushrooms or spiders.Beneath the lawless Calarata, the young dungeon core will have to fight to survive; and one day, he will return death to the man who killed him.

Yan Fei ordered a small drone online. I didn’t expect the drone to suddenly become his avatar.

Magical! Even more amazing is still behind, this drone can actually be upgraded, unmanned fighters, heavy fighters, stealth bombers…

Is this one thing that is fighting against the sky, is it really my avatar? Is it difficult for me to hang the world?
Yan Fei said Alexander!

- Description from Uukanshu