A Knight wakes up to screams and swords clashing together, once he walks out of his house, he witnesses chaos. The world around them was filled with the chilling breeze of a snow storm along with a melting heat of a volcanic eruption. The Knight sees the world fall apart right in front of him. He has become weak after fighting wars for eternity. His power is still a force to be reckoned with but it may not be enough to defeat the Dark Knights From The Abyss.
The Knight follows the trail of the shadows and makes his way to The Great Castle of Kaen. The castle was built on a volcano which finally erupted after a million years, it awakened the king of the castle named Lord Yōgan. The gatekeeper of the castle informs the Knight, Lord Yōgan knows the answer on how to seal the Abyssal gate. The Knight defeats the Awakened King and seeks answers to stop the chaos. He receives them from the King along with the gift of his Flaming Sword and souls of the ones who the King took away in the past to protect his kingdom.
The Knight then goes on his way to seal the Abyssal gate and to do that he must cut off the roots in the two different realms which link the main root to weaken it. To do so he must possess the power of the Death God named – Bushūgi and Sword of the Abyss from The Abyssal Gatekeeper Shin’en Kantoku.
The Knight goes on his path to the Realms. The Warden informs him the changes to his state of being upon entering each of the realms. In the first Realm, the Knight has a chance to be corrupted by the Abyss if they stay in there for too long, this Realm tries to keep the outsiders away in order to protect The Order Of The Abyss. Upon corruption the Knight has a chance to purify himself with Blessing Of The Flame from Lord Yōgan by sacrificing Dark Knights Of The Abyss to the flame.
In the next Realm, The Area is control with the Spirit Of The Wind; to the path the Knight must follow the wind and let it lead the way, if the Knight is lost, they can return to where they began the path in that realm at any moment by using the Blessing Of The Wind granted as a Birth Gift to the Knight.
Once the Roots are destroyed from both of the main Realms, the Knight must seek true power, and to do so, They must enter the Death Realm to defeat the God Of The Death – Bushūgi.
When the Death God is defeated, the storm approaches and swallows almost the entire world caused by the instability of the souls moving out of the Death Realm. After the victory against the Death God, the Knight’s only fight is left in the Last Root Of The Abyss, with the immense new power, stronger than the Knight was ever before, ravages their way to the root and is offered two choices from The Dealer – The Knight could rule the Abyss and gain immense power and immortality, or can destroy the root and end the suffering of the people in the Mid-Realm.