Twenty-eight years after the death of the hero Himmel, the elf mage Frieren and her apprentice Fern travel to the trading city of Waal. Frieren's true goal in this region is to check on a seal holding back an ancient, powerful demon named , known as the "Elder Sage of Corruption".
: Eighty years ago, Frieren's original hero party could not defeat Qual. He had developed a revolutionary spell called Zoltraak —"Killing Magic"—which bypassed all contemporary human defensive magic and gear. Lacking a way to block it, the party chose to seal him away instead. Twenty-eight years after the death of the hero
Frieren: Beyond Journey's End - Episode 3 discussion : r/anime He had developed a revolutionary spell called Zoltraak
: Frieren explains to Fern that in the decades since Qual was sealed, human mages studied his spell. They eventually "standardized" it, incorporating its principles into humanity’s own offensive and defensive magic systems. They eventually "standardized" it