A Wizard's Secret - Chapter 1051 - Limits!

He Lang died by his own hands for the sake of his imperial younger brother’s ambition, whom he loved. He was offered to be reborn in exchange for giving up his past romantic feelings. Reborn without the burden of his romantic feelings, he brings with him a manual to new worlds. He wholeheartedly followed the instructions of the manual to complete the tasks, not knowing that the originally slag gong was blackening…
He pleaded to his affectionate Emperor brother to release him, he pleaded to the paranoid prisoner next door, but until the end he remained baffled.
In the end, he discovered that the full name of the manual was – “Slag Shou Cultivating Manual”
Σ (っ ° ° °;) っ!

- Description from Novelupdates

Kuramoto Daisuke, a freshman in High School was suddenly exposed to someone vanishing in front of him. Turns out he was admitted to a Special Class full of Isekai Heroes that were regularly summoned to Otherworlds since the start of their Middle School. He was told that he was to become their Support to prevent each of the Heroes' fate of dying in the world they were summoned into. Though mediocre, he realized that his ability has a great potential but it needs a lot of hard work on his part.

Unconvinced of being just the Support Character, he vowed to excavate his mediocre ability, all the while supporting the Heroes using it.

And maybe more.

A generation of hegemons, betrayed by betrayal, besieged by forty-nine strong men, tragically killed and robbed the mountain, re-lived once, he will re-enter the peak; strong rise, into the chaotic star field, exhausted 100,000 strong, Wusheng dead and kill, The impact is high!

- Description from 69shu translation

[The Demon King is Dead], a story in which the Demon King got immediately killed in the Prologue. I became the ‘Demon Prince’ of said novel.

…Help me.