The Tyrant Empress is Obsessed with Me - Chapter 18:

Vincent Strider was a gun for hire who made a living by killing whoever it was his clients wanted dead. But during one mission, he died in a fierce gunfight. However, death was not the end for him. Vincent found himself reincarnated in another world, facing a floating interface that flickered before his eyes.[Synchronizing Host!][Military System initializing.]Vincent found out that in this system he received, he can summon soldiers, tanks, aircrafts, and even warships! This is going to be exhilarating.

The Adrasia empire on the Vogel continent. There is a battle over the throne of such an empire that possesses powerful military and vast territory.With the successor undecided, the children of the emperor are vying to expand their power. However, there was one prince that everyone says will definitely not become the emperor.The seventh prince, Arnold Lakes Adler. The young man who was inferior to his younger twin brother in every way, the dull prince.Incompetent and lethargic, Arnold wastes everyday just playing around. However, behind the scenes, he is one of the only five SS-Class adventurers called ‘Silver’.Seeing the intensifying battle for the throne he decided “I don’t want to die so let’s have my little brother become the emperor…”This is the tale of absurd secret manoeuvres of the prince who is uninterested in the title of the emperor.

Humans across the world ended up joining a “Demon Kings and Heroes game”.

Several billion people were set down upon another world to act as “Demon Kings” and “Heroes”. Everyone has to chose their starting races from the start.

Zhang Nu was set in the Demon King camp.

He discovered that he could see hidden information that no one else could.
[Slime Demon King]. Low grade demon king bloodline… Not recommended!
[Kobold Demon King]. Low grade demon king bloodline… Not recommended!
[Dark Elf Demon King]. Mid grade demon king bloodline… Can be selected!
[Bloody Giant Demon King]. High grade demon king bloodline… Recommended!
[Abyssal Dragon Demon King]. Strongest starting bloodline… Extremely recommended!

To save a doomed fantasy world, I killed the main characters, then destroyed the game world, and fell into another timeline as the academy's top seat and rival to the protagonist.Now, I'm trying to save the world and steer it towards a better ending…But I'm the final boss.