20 years ago, exactly in 2004, humanity was shocked by the appearance of a mysterious structure. Strange and dangerous creatures suddenly appeared from inside the structure. However, thanks to advances in technology, the crisis was overcome and the monsters stopped coming out. 
But still, the structure continues to” give birth " Monsters of various kinds endlessly. Therefore, the world government made a move to prevent the attack of monsters in the outside world. That is, forming a conquest guild that contains people with special abilities with certain symbols on their bodies. 
Various nicknames were given to the structure, ranging from Labyrinth, Abyss, Dungeon and the most famous is the “Dimensional Gate” or often abbreviated as DG. 
Modern weaponry does not function within the DG, but instead, humans exposed to the mysterious energy from within the DG have the ability to control one of several natural elements. It is they who are referred to as “Dimensioners”, Warriors with one of three symbols on their bodies. They continue to fight desperately, some are fighting for the salvation of the world, as well as their own wealth.


Ω : Warrior
∆ : Caster
π : Archer

Dimensional Gate

The sun rises as usual, people work so hard. Passing through the streets. High school girls go to school in their uniforms. Life in the town of Rivelville looks very normal. 


 “Dad, Where is mom?"asked the 5-year-old boy. He stood at the door of his house with his father sitting in his shoes and office coat. Dad replied calmly, “your mom is shopping, Kaiser, be a good boy and wait for your mom to come home before you play outside, okay?” 


The boy nodded slowly and took another sip of the milk box in his hand. 


 This normal life goes on, like water flowing in a river. 


 However, when happiness is on your side, there will be problems. There will be only— 


 A violent shock suddenly occurred, the father protected his son by hugging him and taking him outside. What happened? 


This high-magnitude earthquake was so terrible, the buildings just collapsed, on the coast of the sea water did not escape raging and swept the land. A large crack appeared in the middle of the city, before finally— 


A giant alien structure appeared in the middle of the city. Towering height of about 50 meters. 


People were silent for a moment. All of them were surprised by a foreign object that suddenly appeared like a tree growing out of the ground. 


However, in a few moments, the doors of the alien structure were forcefully opened, swarms of aliens sprung up with sharp weapons in their hands. 


 The gun was fired, although some fell, but still the monsters were still arriving. Tearing the innocent to pieces. 


 In an instant, the world was instantly engulfed by a mysterious crisis. The soldiers began to arrive fully armed. “Damn, there are too many of them!” "Do not give up! Keep hitting them!” 


 “Many civilians have been killed!” 


 Riots broke out everywhere, a child who lost his mother and father, and parents lost their children. Blood everywhere. 


 What exactly happened? Is this what people often say? 


 “AARRHHGGG!!” A little girl screamed loudly, her arm was suddenly injured by itself, but the wound was not like a sword cut, it formed a symbol. The pupils of the child's eyes turn red. 


 Not only her, but many others have experienced the same thing. Both adults and children. 


 “Kaiser! Kaiser! Shit.. It was like burning” Kaiser's father covered the mysterious wound that appeared on his forehead. They both experienced the same thing. 


 On the back of Kaiser's hand appeared a symbol resembling the Omega symbol (Ω) while on the forehead of Kaiser's father appeared a symbol resembling the Delta symbol (∆). What's really going on here? 


 “It happened all of a sudden, the little me couldn't even bear the pain caused by the appearance of the resurrection radiation symbol. My father-became a Dimensioner after learning the fact that my mother was killed as a result of the attack of the monsters.” Adult man sipping liquor while staring at the symbol on the back of his hand. 


 On his waist was a sword, with armor covering his vitals. 


Meanwhile, the girl who was younger than him sat in front of him while listening to him tell a story. “It was a year before I was born, even so, I could feel the horror of the incident.” He said. "Leviathan, although that symbol of resurrection has appeared since you were born, are you sure you are not a Dimensioner?” 


 20 years have passed. Kaiser has grown into a tough guy, a lot has happened lately. Thanks to the symbol in his hand, he could unleash a power equal to that of the monsters. 


“There is no reason for me to fight, Kaiser. I'm not like you who lost your family.” 


 The conversation is over. Kaiser decided to leave there. “The reason I fight is not because my mom was killed or my dad forced me. But—“ for a moment he stared at the wide open door of the cafe, "I wondered what was inside.”


Prologue: Mysterious Structure Appear