Fuse, writer of That Time I Got Reincarnated as a Slime, reportedly was annoyed that he hadn't been contacted in part because he thought the idea of an evil version of Rimuru would be interesting and he would have been willing to help brainstorm ideas.
Related Trivia Tropes:
Creator Backlash: In addition to being canceled after one chapter, it's very obvious that the magazine publication in question, Kadokawa's Dragon Age and mangaka Homura Kawamoto, want nothing more to do with the series ever existing, both of them putting out official apologies about the series on their social media accounts and officially disowning the project.
One-Episode Wonder: The manga was cancelled after a single published chapter due to its extremely poor reception from readers.
Orphaned Series: The manga's abysmal reception killed it after its first chapter.
