Skadi is an Ægir-Seaborn hybrid supersoldier who lost her family during childhood in a tragedy caused by the monsters. She was taken into the Abyssal Hunters project and was engineered to hunt down and exterminate the abyssal monsters. However, Skadi barely survived the devastating war against Ishar-mla and other Seaborn "gods" and luckily escaped to the shore. She has since disguised herself as a stoic bounty huntress known by the bizarre title "The Walking Catastrophe" thanks to her enormous strength as a Hunter. Fearing that her Seaborn blood would corrupt herself as well as bringing danger to others, she prefers to be alone most of the time, leading to her uneasy relationship with the land-dwellers. Back when Skadi opened her eyes on the beach, she found not a single soul by her side. Ægir. Abyssal Hunters. All lives on the line, flesh to flesh, blood to blood. None of it seemed to exist. Countless times she tried to return to the ocean. But every time, countless sea monsters would surround her, forcing her to turn back midway. At some point, she felt that the abyssal infinitiude of monsters were not pursuing her, but rather sending her off. Once she became aware of the possibility she may never return to the sea, she had no choice but to turn around on the shore and set foot onto this land she'd never been concerned with before. Nevertheless, R.I. employes her to help her investigate more about the current condition of isolationist underwater nation and the surviving Hunters.

For now, Skadi uses everything she has to counter her Seaborn influence. But what if she fails? What if her Seaborn blood accidentally merged with Ishar-mla's during that war, turning her into His mere vassal in the process, leading the seaborn to destroy every civilization and slaughtering her fellow Hunters to the last man? Only Skadi herself knows the best.

— For so long have I wandered the dry land, looking for fellow Hunters... but now, Gladiia and Specter both are here... Hm? Ah, Doctor... you shouldn't get too close to me.