(Third Person POV)
As the attack landed, Acnologia began to release an immense amount of magic power which began to shake the domain violently.
Jason widened his eyes, "W-What?" He said
The Dragon King waved his hand and dispersed the pitch-black wave of darkness, "This is nowhere near enough, Jason!!!" He bellowed with anger, "You think that using the Eclipsed God's weapon will kill me? It's futile!!!"
Acnologia's arms began to be engulfed in a dark grey energy as his eyes glowed brightly, his body emitting a powerful and thick aura Jason descended from the air.
"What the actual fuck?!" Jason said, "That was a combined attack of the Curse of Ankhseram and The Eclipsed Darkness through the Calamitous Edge!! I had to activate a fucking contract to use this stupid thing!! It was a one-time thing!!!"
"You wasted your chance," Acnologia growled, "Such tactics should only be met with death. To rely on them is purely pathetic. I am above them, they have once tried to slay me, but failed!!!"
He then fired off a breath attack with tremendous speed that Jason couldn't react to it. The beam hit Jason directly, causing a powerful explosion.
As Jason fell to the ground, covered in smoke and flames, Acnologia swung his arms down, gnawing at the air and causing some sort of spatial rift. It was as if his claws were able to rip through the spatial domain itself.
Jason hit the ground, getting up almost immediately as he readied the halberd. He widened his eyes in shock to see the massive glowing rips in the fabric of the domain as the entire thing began to shake. Acnologia's face was distorted with pure rage, his eyes emitting a bright grey light as his entire body released magic power.
"No fucking way..." Jason said, "He's...."
Acnologia reared his head back and let out a vicious roar, releasing a powerful wave of his pure magic power, breaking the entire ground itself as the Domain began to collapse. Acnologia's power was so great that even this Spatial Domain was not enough to fully contain it, under normal circumstances.
"He's collapsing the Domain with pure magic power?!" Jason exclaimed with shock, "What kind of fucking monster is he?!"
At that moment, Jason had decided on one thing; it would take something more than that to contain the monstrous power of Acnologia. He had attempted to defeat the Dragon King with his God-Killer weapon, which failed. He had attempted to nuke him with his W.M.D. which is an incredibly devastating weapon that is capable of destroying everything and anything, which also failed. At last, he attempted to use the Calamitous Edge by combining the Curse of Ankhseram and Eclipsed Darkness and failed.
And right now, the Dragon King was forcing his way out of the domain, causing it to collapse completely. This was a feat nobody, not even Jason was capable of doing.
In an instant, something that even Jason couldn't understand, they were back in the real world, barreling through the air.
Acnologia had collapsed the domain and caused both of them to be in a free fall in the physical world.
"Shit..." Jason said, "I ought to-"
Jason then coughed up blood as a hand impaled through his chest as he looked into the eyes of Acnologia, who had run his claws through him.
"I think this is enough." Acnologia said, "I must commend you, Jason. I believe you may have caused more damage than the Black Wizard would be capable of doing. But who knows, He may have tricks up his sleeves too. I shall end you here and now, and proceed to slay all Dragons in this continent."
Jason attempted to raise the halberd but his body wasn't listening to him; the Calamitous Edge slipped through his fingers and fell. Jason looked to see the halberd plummet to the ground and somehow disappear, the entire thing being sucked into a black vortex.
Jason then looked at Acnologia and weakly grasped the arm that was impaling his chest, using all his strength in the action.
"You...." Jason managed weakly, "You're a monster...."
Acnologia looked at him seriously, "And so are you..." He said, "I will not forget your name, Jason. You were a true warrior. My eyes did not deceive me when I first saw you. You truly are the spitting image of him, Jason Glory."
Jason then clapped his hands, releasing a wave of blue magic power.
"I'm....not done....yet..." He managed
Acnologia widened his eyes, "Another attempt?" He said, "What is this?!"
Acnologia wasn't surprised at the impending danger of what Jason was doing, he was more surprised that Jason had enough strength to even cast a spell. He had impaled his chest with a magic power-enhanced attack, meant to burn through his organs and magic power.
"Spatial Domain: Rocky Sea-Side Landbridge"
They were both sucked into a single point, taken into the Domain.
As they both landed on the landbridge inside the water domain, Acnologia looked around in annoyance.
"Do you think this will contain me?" He said, "Even the domain with the overwhelming Curse Power was far from enough. I shall simply collapse it like I did that one!!!"
As Jason got to his knees, a massive tidal wave hit the Dragon King who attempted to release his destructive magic power.
"What?!" Acnologia said, "What is this?!"
The Dragon King was hit by several waves that began to swirl around him, keeping him in place. He then noticed that they were washing his magic power away and due to the immense amount and its potency, it resulted in a vicious swirling torrent of waters that constantly hit the Dragon King.
Jason then straightened up, his hole slowly closing as blood came out of his mouth. Acnologia then noticed a strange dark purple crystal shard in his hand. He could sense an immense amount of magic power emanating from it.
"W-What's the meaning of this....?" Acnologia said
"You're too damn strong, Acnologia." Jason managed as he panted, "No matter what I threw at you, you merely shrugged it off. I can't have you going around wrecking shit in this war, no. I have to defeat Zeref and his stupid Empire without you running around endangering my son."
Acnologia raised his eyebrows, "Son?" He said with a hint of surprise, "The Black Dragon is your son?"
Jason nodded, "Yes." He said, "Now you understand, do you?"
Jason slowly raised the shard.
"Void Prison: Sacrificial Key"
He then lunged at the Dragon King and through the torrent of water, he plunged the shard into his chest.
Upon being pierced by the key, Acnologia's body emitted an intense purple light which caused a shockwave that sent Jason flying back. Acnologia then began to feel an intense burning pain all over his body as the torrent of water coiled around him.
"A-Aghhh!!!" Acnologia yelled out, "T-This!!!"
"I hereby sacrifice this domain to cast you out!!!" Jason chanted as he pointed his open palm at Acnologia, "The Sacrificial Key shall seal you into the Void!!"
Jason's palm emitted a bright purple light.
"Void Prison: Banishment Seal"