Mash-Up: I'm Not A Substitute - Chapter 15: Shijo Maki has sent you a date invitation.

What if Midoriya Izuku stayed quirkless? What if he could become a hero without any powers? Or even more shocking—what if he became the successor to All For One?

Xu Yiyang, who was only late in his life when he was middle-aged, returned to 1999 in a dream.

At the turn of the millennium and the turn of the century, he realized a truth:
Not only to be famous early, to start a business and make money, but also early!
………………
New book uploads, new stories, new voyages,
Hope you all support!

- Description from Uukanshu

In a world where the very fabric of reality is held together by fragile threads known as the Veil, humanity faces an ever-present threat from the void—a dark, consuming force that seeks to unravel everything. The ancient Guardians once stood as protectors, weaving powerful Knots to keep the void at bay, but their knowledge has faded, and the Knots are beginning to fray.Cole, an unlikely Weaver with the rare ability to sense and manipulate the threads of the Veil, embarks on a perilous journey alongside the skilled warrior Selene, the stoic guardian Marcus, and the enigmatic scholar Elara. Together, they must navigate a land ravaged by void-touched creatures and discover the forgotten secrets of the Guardians to repair the Knots and stop the void from consuming their world.But the deeper they delve into the mysteries of the Veil, the more they realize that the void is not their only enemy. Hidden forces work from the shadows, manipulating the fraying threads for their own gain, and ancient powers thought long buried are stirring beneath the surface. As the Knots unravel and reality itself begins to fracture, Cole and his companions must face not only the void, but the dark truths of their own world—and themselves.withHeart is a gripping, character-driven epic of survival, sacrifice, and the delicate balance between light and darkness. The series explores themes of destiny, power, and the fragile threads that bind us all together, weaving a story where every choice could mean the difference between salvation and oblivion.

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.