Mipherius

Mipherius (ミフェリアス) is a spin-off character created for the That Time I Got Reincarnated as a Slime: Isekai Memories x KonoSuba collab.

Appearance
In his initial form, Mipherius takes the form of a knight in a suit of plate armor wielding a halberd. Instead of a face, he instead has a mass of purple smoke with glowing blue slits for eyes.

After being pushed into a corner, Mipherius uses his ability to assume a monstrous form that combines Charybdis and the Giant Toad from KonoSuba, referred to simply as Charybdis Toad.

Personality
Mipherious is an individual filled with Envy; Envy for those who succeed where he has failed. He bears an irrational hatred for those who are "lucky" who are Otherworlders who succeeded here, calling those with overpowered abilities "cheats" and plotting their downfall. He's the embodiment of a stereotypical sore loser, the type that shouts "Normies Explode" when they see a happy couple on the street.

Background
Mipherius was born from the collective resentment of various human Otherworlders who were "failures". Those who were reincarnated but died as infants, those who were summoned but died in the process, and so on. When he was born, he had gained two special abilities, those being "Interdimensional Travel" and "Concept Fusion". Using these two powers, he began to go universe to universe hunting down Otherworlders that had succeeded where the souls that Mipherius was made of had failed.