Counterattack System appeared when I'm already At The Mahayana Realm - Chapter 6 - : I am the Brother of the Human Emperor Jiang

Hutson, a man reborn into a ruthless and dangerous world, now inhabits the body of a young hunter in a small barony. With no connections and nothing to his name, he must rely on his sharp mind and cunning to rise through a medieval-like society. As he climbs the social ladder, he uncovers a terrifying truth: wizards, beings far more powerful than any knight or noble, rule over the world. Driven by this discovery, Hutson throws himself into the pursuit of wizardry—a path darker and more brutal than he could ever have imagined. In a world where betrayal lurks around every corner, Hutson seeks what all others desire: immortality. With his intellect and ruthlessness, he will stop at nothing to claim it for himself.

High-school student Koremitsu Akagi finds himself attending the funeral of Hikaru Mikado, who had died in an accident during Golden Week. He’s not sure why he’s there, as he only exchanged a few words with Hikaru at school. However, Hikaru doesn’t seem to be completely gone from the world, as he comes back as a ghost in order to fulfill a promise to Aoi Saotome, his fiancée. Since Koremitsu is the only one who can see him, he asks him to carry out his promise in his place.

Complying with his request, Koremitsu tries to fulfill Hikaru’s promises to the rest of his “girlfriends”, helping them overcome past misunderstandings and repair broken relationships.

The doomsday fell upon the earth when a dragon coffin sealed under a snow mountain for ages shifted, and the civilization of gods and devils began. The whole universe turned into a fantastic new world where everyone could rise to the top through cultivation. A lucky young boy seized the opportunity, and started his journey to be an overlord in cultivation.

- Description from Novelupdates

He put one hand on the door beside her head before leaning forward. What was he doing? Trying to intimidate her again?