It seems you're referring to (破滅の願望 第一章), which translates roughly to “Desire for Ruin: Chapter One” — possibly a doujin music track, a game BGM, or a fan-made composition, given the stylistic naming.
He stood before it, watching his own reflection splinter — not into fragments of glass, but into memories. Each shard held a failure: a word unsaid, a hand unclenched, a city he had watched burn from a safe distance. And yet, he smiled.
No answer came. Only the sound of his own heartbeat, syncing with the slow collapse of the floor beneath him. Hametsu no Ganbou Daiisshou
If ruin was the answer, then he would become the question.
This was not madness. This was purpose.
He reached into the largest shard and pulled out a black flower — petals made of ash, roots made of regret. It bloomed in his palm, and with it bloomed the first note of a song that had no end.
The first crack appeared not in the sky, but in the mirror. And yet, he smiled
“Is this what you wanted?” the mirror whispered.