Across Finland, the realm and goings-on of Death are managed by Oblivion Co., a vast family business owned by King Tuoni and Queen Tuoneta of Tuonela. Theirs is a most morbid family, whose every member has their own unique and grotesque obsession with the deaths of human beings (except for Kipu-Tyttö, she's a sweet). Oblivion Co. is in the business of employing its bosses' offspring—and there are a lot of those to go around—hundreds, in fact, each of whom specialises in a specific kind or aspect of death.
Kalma is the second daughter of the couple, and it was almost inevitable that she would join the ranks of the family business eventually. The role she was accorded (of utmost importance according to Tuoneta) was to return dead things to the soil by making them decay. Amid her family's illustrious history of perpetrating violent death and suffering among the living, she is a bit of an odd-one-out, drifting about on a breath of air and flame, quietly tidying up after her siblings and niblings after they've done the dirty work of squeezing souls out of corpses.
Over millennia working among dead bodies, the scent of decay has rubbed off on her, and her stench precedes her wherever she goes. Finland is a much cleaner, safer place thanks to her—imagine the hazard posed by diseased corpse parts lying on every street—but no one appreciates her for it, concerning themselves instead with getting as far away from her and her pungent odour as possible.