"When I Reincarnated as a Mantis in Another World, They Call Me the Grim Reaper"

I was a college student working part-time at a convenience store when a robbery occurred. One thing led to another, and I died. I was reborn as a mantis in another world. This is the story of not just one person, but one creature—a mantis that decided to live on in this other world and enjoy life there, eventually becoming an existence known as the Grim Reaper. The protagonist is overpowered. Eventually, the story follows this creature as it becomes a Demon King, destroys other Demon Kings, recruits them as allies, and even battles against gods.