Rem is one of the twin maids working for Roswaal L Mathers. She tends to speak in a superficially polite manner and sometimes acts without thinking. She holds both worshipping respect and guilt toward her sister for an incident in the past; because of this, Rem tends to think of herself as inferior. (Source: Re:Zero Wiki)

An arch wizard who is descended from crimson demons; powerful humanoids who possess black hair and red eyes, and sport chuunibyou characteristics. Megumin only knows a single skill, the incredibly powerful explosion magic that immediately incapacitates her for the rest of the day when cast, and refuses to learn any other skills. (Source: Wikipedia, edited)