Klem is a major supporting character in Isekai Maou to Shoukan Shoujo no Dorei Majutsu. She is a powerful demon lord candidate and the ruler of the Demon Lord’s territory known as the Great Demon Lord Klem. Despite her intimidating status, she often appears childlike, emotional, and somewhat eccentric. She becomes closely involved with Diablo and the heroines, serving as both an ally and a source of comic relief, while also influencing the political and supernatural conflicts in the series.