Invincible from Seeing the BOSS's Health Bar - Chapter 4 - Monster

I killed the protagonist.Yeah. He was a real son of a bitch.Noah didn’t just stumble into this mess. He walked straight in—grinning, sword in hand.One day, he wakes up inside his favorite game… as a throwaway side character no one remembers. A complete nobody. But when he figures out who the so-called “main character” is?Some smug, self-righteous psycho.So yeah—he killed him. No regrets.Story over, right?Not exactly.Because this world? It’s got one more player.“WHAT THE FUCK IS GOING ON!?”Now the story’s off the rails, the world’s gone completely off-script, and Noah’s got a new goal:Steal the hero’s spot. Rewrite the plot. Find out who the hell this other player is. And maybe—just maybe—make this damn story fun for once.

After being wrongfully accused and killed, a young man reincarnates into a superhuman society as a third rate villain named Don, whose biggest asset is his side-kick with mental issues. With few options available to him, Don accepts the mantle of his predecessor and must now not only survive in a new and dangerous world, but also conquer it....**Congratulations, you have died and awakened the Supervillain Idol System.****The path to fame, fortune and world domination is yours is take!!**

Power and desire, money and strength, conscience and responsibility, the road ahead is at a loss, as a time traveler, Simon, where will he go, this is a leading mainstream novel with a relaxed daily life and a slow pace

- Description from novelbuddy

Failing in his job hunting, Sanada Kyouichirou was hopeless in this society. When kyouichirou had thrown himself towards the bottom of a cliff. When he woke up his body had returned towards when he was in fifth grade of elementary school. He did not want to have any regrets in this life so he had decided on building up an harem in this second life.

The elder sister that he admired, a senior and president of the student council at a school for rich young girls, a strong minded upper classman at school. The poison fang of Kyouichirou who had pretended to be a innocent child attacks those girls.