The sound comes from the Touhou Project, the long running Japanese bullet hell series created by ZUN of Team Shanghai Alice. In those games bosses are defeated after spell card phases, and their death is marked by a distinctive short explosion that players hear after some of the hardest fights in the genre. Clips and fan edits shared the effect outside the games, and it became a shorthand among Touhou and gaming communities for a boss finally going down, which keeps it popular for memes and edits.
About this sound
This boss death sound effect is the short explosion heard when a boss is defeated in the Touhou Project games, used for game over and fail edits online.
A split second long, this is the sharp popping explosion that plays in Touhou Project bullet hell games when a boss runs out of health. It is not a long cinematic blast but a tight, percussive burst with a bright electronic edge that cuts through dense danmaku and music. Hearing it instantly signals victory after a frantic spell card fight, which is why it feels so satisfying and abrupt at the same time. Dropped into other footage, it turns any small defeat or collapse into a clear, funny game style knockout.