Blue and Red Tide

Azeria, a dimensional world illuminated by cyan light. A giant tower-like spiritual energy well stands on the ground, where the dead "turn into light" and the living can live in peace. This is a world that has been ruled by the Sanctuary for hundreds of years - they have great power and are determined to fight against the "undercurrent" that destroys the world. Whenever the world declines, the demon king named "Undertide" will return from the void: it is the shadow of destruction caused by the collapse of the world. It is almost immortal. After its physical body is defeated by crusade, it will be resurrected again to harvest all living beings with disasters. The Sanctuary recruits soldiers to fight against the undercurrent and win the hearts of the people as a savior. No one asks where the disaster comes from. The young warrior Kyle is the sharpest sword in the sanctuary. He only trusts the sword in his hand, which is fast, accurate and ruthless. He was ordered to attack the undercurrent, hunt down its followers, and destroy the altar. He was from a lower class background, and had seen the tragic scene of corpses being destroyed by the souls, but he always believed that it was the grace of the sanctuary to purify the dead souls - he thought that protecting this world meant protecting everything.