The Holy Kingdom of Gusteko (グステコ聖王国), usually referred to as Gusteko (グステコ), is a country located to the north of Lugnica.
It is a theocracy currently ruled by a mad prince. As it is located in the north, it is a cold country, and has an extreme disparity in wealth, with child abandonment common among the poor.
An assassin organization led by a person known only as Mama is also based in the country.
Many years ago, after the creation of the pact with Farsale Lugnica and Volcanica, the sorcerers moved to Gusteko from all over the continent. They we're famous for killing people with various spells known as a Curse (呪い), however these are just a subclass of users of magic and spiritual arts of the place, some people comment that "they are useless" and that "you shouldn't take them seriously".