WARNING: Mildly Warm (High School DxD/FateNasu Chapter 2)

Rias didn't expect herself to be facing a whole group of Fallen and their squad of Stray Exorcists, on this simple investigation. The explosion of magical energy can easily be explained by an amateur magician experimenting with their spells. That she could easily deal with, with Sona working on the mass memory spell to fix everything afterwards.

A sudden battle before a burning house, in the urban area, with people screaming and-thankfully-running far away, was not what Rias planned for.

"You attacked a human. In their home. Causing unprecedented chaos, in my territory." Rias' tone was one of someone about to go on a warpath, as her demonic aura erupted from her. "I hope you all have enjoyed yourself, because your fun ends here. Permanently."

"Funny enough, this wasn't us, but the pervert was one of my targets, so I'll take this as good fortune anyways." Raynare said, before a wide vicious grin came to her face. "And we even got a bigger catch from this surprise. So hell, I'm grateful for that idiot human for getting himself killed. Didn't think I would land in this perfect situation to take down this pompous princess."

"We're gonna kill, rape and all you all, you filthy devils!" Shouted Freed Sellzen with an manic grin. "And not in that order."

"Don't kill the Gremory girl. Other than that, have fun." Raynare order with a smile.

Surprisingly, Freed didn't oppose that order. "Fuck yeah, I am." He held up a Lightsaber and Lightgun, about to charge in with the Stray Exorcists squad behind him.

"That's it." Rias summoned her Bael Trait to her hand, the Power of Destruction. Her anger such that she didn't even think to tell her Peerage, for one of them to search the house for any survivor. "You just signed your Destruct-"

Thankfully that wasn't needed.

The window to Issei Hyoudou's room exploded as something crashed out of it, cause the flamed to raged out behind whatever flew out.

It was a giant ball of fire.

"AAAAAAAAAAAAAAAAAAAHHH!" There was screaming.

No. It was a person surrounded by fire.

And as the fiery figure landed on one knee, making the flames surrounding them blast in all directions, making a scorched circle upon their landing, the figure was revealed to be a redheaded woman carrying someone in a princess carry, as she stood up.

A tall redheaded woman in a leather suit, with flaming red hair, carrying the unconscious body of Issei Hyoudou.

A moaning Issei who fainted from sheer fright of all the sudden action.

"Hmm?" Nobunaga stared at the two groups she landed rival groups it seemed. "My, my, to think my arrival would cause such a ruckus." She smirked in a way that set the two groups on edge, sans the other redhead present. "So, heaven and hell have come to challenge me upon my summoning. I suppose this is an appropriate welcoming."

"Hey, you red headed slut! Who the hell are you calling 'of heaven'!?" Raynare shouted.

"Ah, I see. I'll correct my earlier statement, you are those who are tainted and were tarnished from heaven." Nobunaga chuckled.

"Oh that's it!" Rayanre and the other Fallen summoning their Light Spears to attack.

"Don't know what strip club you came out of, but fuck it, let's see what else your mouth is good for bitch!" Freed dashed forward.

The Mad Exorcist action signaled the start of the fight as the Fallen launched their attacks, and the Stray Exorcists dashed at this new enemy.

In an instant Nobunaga thought of what to do. The Devils seemed contend to just stare at her in confusion, while the Fallen and Stray Exorcists were trigger happen. Also the Devils were more focused on the Fallen Angel and their group, rather than on her. That made things easy.

The moment passed, and in the next hundred of floating muskets materialized around Nobunaga, and fired upon the Fallen Angels group.

It was instant slaughter. The magic bullets, empowered by Nobunaga to reject any Mystery or Divinity, tore through the Light Spears, the Lightsabers, even the bullets fired from the Stray Exorcists' Lightguns, mowing down those that only attempted to fight her.

Only Freed managed to avoid the magic bullet onslaught reaching two meters close to Demon King.

Nobunaga adjusted her hold to carry Issei with one hand. She summoning flames to her hand-which had the effect of dragging the fired of the house to her as well-and made her blade, whose metal was reddish orange as if made of hellfire and never cooled.

Faster than Freed could even conceive, her arm moved.

One swing.

The Mad Exorcist never realized his body was sliced in half, as flame arcs exploded after the sword swing engulfing Freed whole and incinerating him on the spot.

"S-So quickly, and so easily too." Kiba muttered.

"Oh. Lucky coincidence. Good." Nobunaga said as she looked at the moderately scorched, smoking, and thankfully, no-longer-on-fire house, before turning to the other group present.

"Now, you however...don't seem hostile." Nobunaga tilted her head. "So what to do with you?"

"...Onee-sama?" Rias said in a daze, just overtaken by the Demon King's presence.

"...Okay, second time that happened." Nobunaga muttered.

"Rias, you didn't tell me you had an older sister?" Akeno asked with a teasing smile. Not fully relaxed, but starting to feel like a fight might not occur. Then again, she definintely wants to do other things to this new redhead after she so thoroughly and effortlessly killed those Fallen Angels.

"I-I don't!" Rias shook her daze off, now blushing quite a bit. "At least, I'm pretty sure I don't. No, I'm sure if I had my parents or brother would have slipped and mentioned her at some point."

A chuckle brought attention back to the Fiery Demon King.

"While I have been labelled a 'Demon' many times when I was alive, I am not actually one in the flesh." Nobunaga chuckled.

"Wait, 'when you were alive'?" Akeno asked, catching on.

"W-Who are you?" Rias asked, slowly getting back her groove as one of the rulers of Kuoh, and a Devil whose King of her own Peerage.

Before Nobunaga could answer, a groan was heard from the person she was carrying. Issei slowing blinked as he woke up. He looked up to see the amused face of Nobunaga looking down on him, and with a girly cry jumped out of her embrace.

"Oh man," Issei panted. "S-Sorry about-MY HOUSE!" Issei held his head, thinking about how his parents will kill him when they get back.

"It's okay, Issei, I'm sure we can fix the damage easily enough." Akeno said reassuringly.

"Oh, thank you, Akeno-sen...Wait, Akeno-senpai!?" Issei started to take stock of the situation. "Rias-senpai? Koneko? Damn Handsome!"

"Why do I feel singled out?" Kiba said to himself.

"Issei, I know you might be a bit confused, but try and calm down. We need to talk about-"

"ARE THOSE DEAD PEOPLE!?" Issei shouted as he saw the Stray Exorcists and Fallen Angels.

Rias sighed as Issei began panicking.

"They were enemies attempting to slay us. Do no mourn for them, for they would not have mourned for us." Nobunaga tried to comfort Issei.

"YOU KILLED PEOPLE ALREADY!? HOW DID WE MAKE ENEMIES THAT FAST?" Issei cried out.

[Boy! You should follow that Devil's advise and calm down, so you may assess the situation correctly.] The Rias and her Peerage now noticed that Issei had a Sacred Gear, and that it was different than a normal Twice Critical.

"Is...Is that the Boosted Gea-?" Rias started to say.

"WHY IS MY FAPPING HAND TALKING? WHAT THE HELL IS THIS DAY?"

Nobunaga threw her head back and laughed.

Sona was cursing mentally all the reckless people she knew and didn't know as she was handling the fallout of the latest event.

Akeno had sent a message to Sona's Queen, Tsubaki, telling her of the situation, that they have it mostly handled, and just asking the person involved in the magic explosion, that started this whole thing.

She couldn't believe it was Hyoudou of all people, that was the cause of this chaos.

She was going to give him a talking to next day at school, of course. If only to vent her frustration.

Sona was glad that at least this chaos was now over.

After Issei calmed down, with Rias and her Peerage providing a simple explanation to what's happening (Devils, Angels, Fallen, Sacred Gear, Great War etc.), in the somewhat fixed house-courtesy of Akeno-it was time for Issei to answer some questions.

"So, I suppose the most important thing is, who is she?" Rias said to the redheaded Servant, who was sitting besides Issei legs crossed on top of each other.

"Haha I...don't think you'd believe me." Issei chuckled nervously, looking to the side.

The Devils looked intrigued, that despite everything that just happened, and what was talked about, the former supernatural ignorant human, was telling them they-the Devils-wouldn't believe him.

"Try us." Rias pushed.

Nobunaga watched on with an amused smirk, deciding to wait a while before introducing herself.

"Well, it all started when I was waiting for my date with Yuuma-chan..."

And so Issei explained his day and the events that transpired, the devil wish contract, the date being halted, him going back home, him trying out the devil summoning and it failing-Rias suddenly felt like this was something she could have avoided, and naturally acted like it wasn't her fault, it was just bad luck-and then...Issei mentioned his improvised magic circle.

"Wait, what?" Rias blinked at few times, as Issei what he did. "Do you have a copy of this summoning circle?"

"I...think it was burned up when her Lo-Ladyship was summoned." Issei replied.

Rias and her Peerage were taken aback by Issei not being fully lustful after a beautiful woman, but polite and deferential to her.

"That is right." Nobunaga spoke, drawing attention back to her. "It was through mere foolishness, yet courage that my First Retainer brought me here. An accident true, and I suspect normally he would have perished."

"Wait, what?" Issei asked with wide-eyes.

"Yet, he had succeeding in calling and materializing me back to the living realm, as an embodied spirit true, yet among the living once more." Nobunaga declared, her words putting the Devils on edge. "As for who I am...if you live in the Land of the Rising Sun, then you'd know of me." She grinned and continued.

"I am the one who made themselves the enemy of gods, buddha and all living things." The Devils drew a blank, but were thoroughly worried by that title.

"I am the King of Innovation." The Devils drew a blank.

"Conqueror of the Warring States," Rias and her Peerage sat up at alarm. That was not a simple title to throw around. Not many can dare claim it. Rias especially was beginning to feel her heart racing.

No, it couldn't be. The Gremory Devil thought.

"First Unifier of Japan, The Great Fool of Owari," Nobunaga said with a hint of fondness, and a smirk.

IT IS! Rias' eyes widened, as did Akeno. Kiba and Koneko didn't catch on yet.

"The Demon King of the Myriad Heavens, Oda Nobunaga!" She finished with a wide grin, spreading her arm wide, as flames dramatically burned behind her in the image of a flaming skull.

Koneko and Kiba understood then. Akeno covered her open mouth, wanting to despite this, but...it was possible.

Rias however had a different reaction.

"EEEEEEEEEEEEEEEEEEEEEEEEEEEE!"

She squeaked so hard, the windows' glass began to rattle.

"THE HOUSE IS BURNING AGAIN!"

And Issei was shouting in worry as the flames Nobunaga summoned for dramatic flair, weren't under her control for long.

"CAN I HAVE YOUR AUTOGRAPH! NO! CAN YOU PLEASE ME MINE!?"

"HELL NO! I CALLED HER FIRST AND HELP ME TAKE OUT THE FIRE!?"

It would be a few days later, that Sona and Rias were discussion the Hyoudou and Resurrected Warlord Situation.

"You need to expel her. Send her back to the afterlife. She can't stay here." Sona argued.

"Absolutely not!" Rias slammed her hand on the table. "We are not exorcizing a Japanese national treasure! Besides, she hasn't done anything."

"She set fire to Hyoudou's house when she was summoned. She literally said she wants to reconquer Japan!"

"She said she wanted to explore it!"

"So she would know how to reconquer it!"

"She's been nothing but polite and kind and-"

"You're just saying that because she looks like a female version of your brother, while her powers look like the love child of you and Riser."

"EXCUSE YOU-"

An explosion suddenly happened in one of the school buildings.

Rias and Sona tabled their discussion as they made their way to the thankfully empty sports building to see Nobunaga finishing burning some Tengus and Shisas alive, with Issei looking like he got into a scuffle with one of them, and somehow beat them.

After calming things down, taking care of the memory wipes that need to happen, assessing the situation Sona told Issei, Rias, Nobunaga and the members of both Peerage what she found.

"They seems like assassins sent by the Youkai Faction." Sona said. "From what I understand, certain individuals, heroes from history, can sometimes be reincarnated to some degree in modern times. However, certain heroes, that would throw the world in disorder tend to be feared by the current factions maintaining the statue quo."

"So wait, they're just attacking Nobunaga, just because of something she might do? The hell!?" Shouted Issei.

"Calm down, Issei." Nobunaga waved him off. "I can understand their fears. I suppose we should do something to handle this situation in a calm rational manner."

"Yes. Thank you." Sona nodded with a smile, glad to see someone else, with their head on their shoulder.

It was a normal day in Kyoto, home to the West Youkai Faction and the population of supernatural beings that live in it.

"Nobu~!"

It seem like a normal day like any other.

"Nob nob, nobu!"

Yet the people there started to see chibi black haired girls in military outfits, holding all manner of weaponry.

"Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!" "Nobu!"

An army of Mini-Nobu marched across the streets, fighting and taking out any Youkai that opposed them.

And on top of a Giant Golden Nobu, stood the Demon King Nobunaga, with Issei latching to her leg, and screaming in terror.

"YOUKAI OF KYOTO!" Nobunaga's voiced boomed across the area. "I, ODA NOBUNAGA, HAVE COME TO HEAR ALL YOUR GRIEVANCES! LAY THEM BEFORE ME, SO I MAY CUT THEM ONE BY ONE!"