Apollo had been staring at the portal for a while, but he still couldn't stop questioning himself on what's happening, starting from whether this was reality or not, "...W-what's happening?"
And while Apollo was having an existential crisis for putting all of his eggs in one basket, Kisuke stepped forward and started reducing the distance between them slowly, 'To be fair, his basket and eggs were made out of Adamantium, so I can't really blame him.' So when Kisuke found out about their plan, instead of breaking these metaphorically indestructible eggs, he opted to steal and hide them from him.
'I'll throw these eggs at that guy's face if he decides to betray us.' Kisuke chuckled to himself, but the aura he's emitting was far from casual as it was bordering on killing intent.
Kisuke only stopped walking when Apollo suddenly turned to him with a crazed expression, "What did you do!?"
Kisuke didn't answer immediately and watched the 'Gate of Tartarus' close quietly. He smirked at him and replied, "Aren't you the guy who could see the future? You didn't see this coming? It looks like I severely overestimated you."
With all of his plans crumbling in front of him, Apollo lost it and pulled his bow and arrow. This time, putting everything in it with the intention to destroy this entire space. He devolved into a madman who could only think, 'If I can't have it, no one can!'
Naturally, Kisuke wouldn't allow him to do this and finally revealed the fang that he'd been hiding, "4th Gate, Depression."
The instant the fourth 'drum' appeared, the massive amount of Reiatsu laced with destructive Blood Ki immediately exploded outwards. Accompanying it was his blood-red gauntlet and leg armor that he 'couldn't' materialize. Although Kisuke was indeed injured, he didn't materialize his armor on purpose.
But what caught Apollo's eyes was the new addition with the 4th gate's opening, a translucent red floating scarf that wrapped behind him and coiled around both of his arms, '...T-that's!? Divine Power!?'
However, before Apollo could think any further, Kisuke suddenly disappeared from his sight and a very strong premonition made even his own Divine Power act to automatically protect him, 'Death.'
That single word made Apollo realize that there was nothing more important than his own life, 'There's always a next time.'
Apollo immediately took back the power he'd given to his bow and arrow and jumped back while using his final card, running away.
The space behind Apollo suddenly vibrated before it split open, creating a hole just big enough for one person to go through. It was the path of retreat that he'd prepared in case something disastrous happened or those from Tartarus decided to betray him and it should shut itself closed the moment he goes through it. And even if someone reopened it, he'll be long gone.
"I will have my revenge... Hmmm?" Sadly for him, no plan of his has ever come to fruition and even this time was no exception. Thin strings appeared behind the hole he'd created and started sewing it back together at blinding speeds, "!?"
And unfortunately for him, those strings were not the only ones as a few more emerged from his feet and started tying his limbs up. Apollo traced where these strings were coming from and saw a tall woman with long black hair waving her fingers at him with a smile while saying something. Reading her lips, he immediately understood what she was trying to say, "Sayonara~!"
The strings were not that strong and they could easily be broken by Apollo. Nevertheless, that split second he needed to break these were enough to tip the scales between life and death. Apollo saw Kisuke appearing in front of him and struck his chest with his palm, while he stared widely at his terrifying blackened eyes.
"N-"
Apollo tried to say something but immediately lost his ability to do so when a hole in his chest was opened. The next moment, the world in Apollo's eyes started rotating out of control. Even then, he was still able to see his arms and legs flung away because the torso it was attached to exploded into countless pieces. At that point, he'd finally realized what was going on. His head flew away.
A few seconds later, his world stopped spinning and he saw Kisuke's arm on top of his head as he looked at his eyes slowly fading out of life, "You wanted your revenge? Too bad for you, you won't have a turn after I get mine." Those were Kisuke's last words for him.
Before succumbing to eternal rest, Apollo thought to himself, 'I'm really good... At predicting the future.'
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Issei, Vali, Fenrir, and Gog moved towards the Greek-style temple when they felt an extraordinary pressure and a godly aura coming from the temple. Vali prepared to fight as a transportation circle appeared in the air; Hades and Angra Mainyu, who had the appearance of a dark aura taking humanoid form, had arrived. Both Hades and Angra Mainyu possessed terrible auras, with Hades' aura being even stronger than Angra Mainyu's. Angra Mainyu, seeing both of them, admitted he always knew that those dragons were terrible monsters. Issei told them to surrender, but Hades said they wouldn't, though he admitted that even if they won against Issei and Vali, they would have to fight the other Longinus users, Ajuka, Vidar, and eventually Shiva. Hades admitted that there was no possible way they could win in the end.
Vali asked them if they knew that, why did they choose to fight at all. Angra Mainyu pointed out that they have allies who followed them and believed in them despite them knowing this, and that they'd be a joke if they just gave up now. They also pointed out that they just couldn't agree with DxD. Vali laughed while saying it's better than running away at least. There was a flash of light in Hades' eye and he said;
"Go ahead, your souls are showing no signs of weakness, and I will destroy them with my own hands."
The fight split into Vali & Fenrir vs Hades and Issei & Gogmagog vs Angra Mainyu. Issei launched an aura cannon while Angra Mainyu created multiple Zoroastrianism Magic circles and launched various elemental magic attacks. Both attacks collided creating an explosion. They continued fighting each other with Angra Mainyu managing to damage Issei's hands, paralyzing them, and the impact could be felt in his bones. Vali released an aura blast at Hades, who blocked them with his staff and released his own at Vali. They were so powerful that Vali couldn't [Reflect] them properly, so he had to dodge them. Fenrir tried to attack Hades, but he kept dodging and counterattacking him. Hades was avoiding fighting head-on with Fenrir while being wary of Vali. Hades and Vali damaged each other, but since Hades was fighting both Vali and Fenrir at the same time, he was truly a powerful being. Vali contacted Issei through a magic circle, saying that he can win against Hades, but it will be difficult given that they have a time limit.
Issei vs Angra Mainyu fought in an aura vs magic battle, as sometimes Issei would damage Angra Mainyu, and sometimes Angra Mainyu would transform his body into a dark mist to avoid Issei's attacks and transform back. Issei thought of using [Penetrate], but Angra Mainyu admitted that Issei was quite strong and he was going to lose at this rate. Then Angra Mainyu shapeshifted his body into a beautiful woman with black hair, large breasts, a thin waist, and thighs just right. His voice changed to a lovely woman's voice and he was wearing a dress with a high exposure rate. Issei looked away saying that it was too nasty and early for a high school student to see. Angra laughed, saying that this was very effective against the current Red Dragon Emperor as Issei's aura began to shake.
"How stupid." All of a sudden, an intruder interrupted their fight and when Issei turned to her, he muttered in surprise, "Kiryuu?"
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AN: The last part was from DxD wiki except for the last sentence. Credits goes to the contributors of the wiki.
https://highschooldxd.fandom.com/wiki/Hell_Disaster