Advent of Invasion.

A week had passed since Chaldea had officially banded together with the Council of Lucifer and began work under the leadership of the Japanese Faction, and they were starting to get accustomed to life in that post apocalyptic world.

They took a number of roles in order to help the Faction, and under Marth and Flora, they were given their different jobs:

The primary of which was scout and rescue, which is as simple as it sounds, the Servants would join a group of Demons and go out into the dead zone (how the Japanese Faction referred to the remainder of Japan) and search for any signs of surviving humans to bring back into the safe zone.

The second job was to search and destroy any possible Chaos troops in Japan, and report on any suspicious activity that they might discover, so it can be properly dealt with.

Some others, like Da Vinci, Edison, Tesla, Helena, Nemo and Moriarty, stayed behind to guard the Storm Border and oversee its repairs, as well as upgrade it with whatever materials they might find in that new Earth.

Meanwhile, Ritsuka and Goredolf, alongside the strategist like Waver and Reines, stayed in the Council while helping Marth and Flora oversee the state of the Faction.

Aside from his usual duties, Ritsuka had taken a particular interest in the special forces of the Council of Lucifer, the so-called Half Demons. From Marth and Flora, he learned that they were originally humans which through both scientific and magic means, were injected with Demon DNA.

"Why are you so interested in learning about what Half Demons are? Please tell me you're not thinking of becoming one" - Marth said as he and Ritsuka walked together through the hallways of the Diet Building.

"Why? What's wrong with it?" -

"Fujimaru, the procedure to become a Half Demon is highly dangerous and has cost the lives of several candidates. When Flora and myself went through it, we felt the most intense pain we've ever felt in our lives, and I've been stabbed through the eye with one of Hephaestus' swords and Flora has had her entire lower body incinerated" -

"Is that so…?" -

"Yes. Besides, becoming one isn't just going to Mother and telling her. Only the best of the best get the chance to undergo the test to become a Half Demon, and you're…" -

"Not Half Demon material?" -

"Not yet. With the right training, you could be considered a candidate, but even so I wouldn't recommend it, there's a high chance you might just get yourself killed during the procedure" -

"And how did you and Flora survive it?" -

"To this day, I still have no idea. It might have been some sort of divine intervention, pure willpower or simply dumb luck" -

Despite all of what he was hearing, Ritsuka couldn't deny his interest in maybe one day becoming one of the Half Demons of the Council. He would have to work hard if he wanted to even be considered, but that was nothing he couldn't do.

"And what do I have to do to be considered to become a Half Demon?" -

"If you want it so much… First of all that doesn't exactly concern us, Mother is the one who decides it, but with enough accomplishments on the battlefield, you could get her to turn her eyes to you" -

"Does that mean I'm going to join in the fights against Chaos?" -

"If you wish so, yeah. For the next patrol we'll…" -

"Marth! We have news from the Greek Faction, there's a Chaos strike force on the move!" - Flora said as she arrived with the pair.

"What? How long until they arrive?" -

"According to what they told me, 15 minutes before they make contact with Japan" -

"Who's in it?" -

"750 Demons, and they have Ishtar with them" -

"Ishtar huh? Well isn't that just sweet. Call all the teams that we sent out, tell them they need to return immediately. I'll be preparing the defenses" -

"Wait, did you just say Ishtar?" - Ritsuka asked, not fully understanding what was going on.

"Yeah, and if you want to begin your path towards becoming a Half Demon, the best way to do it is by helping us kill the bitch. Call your Servants!" -

Ritsuka did as he was told, and used his Command Seals to call his Servants to immediately return to the grounds of the Japanese Faction and prepare for battle. All of them, at arrival, were confused by the sudden call, but ready to fight nonetheless.

"Who's our enemy this time Master?" - Muramasa asked.

"According to Marth and Flora, we're facing an army of Chaos Demons, led by this world's Ishtar" - upon hearing that, Chaldea's Ishtar yelled loudly.

"WHAT!?" - her scream was heard across all of the Diet Building.

"I don't know either, but we'll have to fight her. Archers, Casters, I'm going to need you in high positions to strike them as soon as they appear. The rest will be with me on the ground, just in case" -

The Servants did as told and took positions around the Diet Building alongside the Demons of the Faction, who were also preparing to fight.

"Sucks that there aren't any other Half Demons besides me and Flora here" - Marth said as he stood next to Ritsuka.

"No others have been asigned?" -

"Not that, just that they're all on other missions. I'm not sure if that bitch Ishtar knew about it and that's why they're making a straight line for us…" -

"What about the Greek Faction you mentioned? Why didn't they try to stop her?" -

"They did. I talked with one of the Half Demons there, Redd, they battled her forces and lowered her numbers greatly, so now she's escaping here. If we're lucky, we'll take her down here" -

The skies began to darken around them, a signal that Ishtar was getting closer. Her Demons appeared from the clouds and started to launch themselves against the Japanese Faction.

Chaldea's Ishtar was the first to strike, launching several bolts of energy towards the Demons, killing them in one shot, the rest of the Archers following soon after. As more and more Demons fell, the figure of a blonde woman showed herself from the clouds.

"What a horrific welcome for the Goddess of Beauty" - she said while faking a sad tone.

"Ishtar, we'll give you one warning, surrender now, and we'll make it painless" - Marth said as blue fire appeared on her hands.

"Aren't you a bold one, little Half Demon? You're attitude is adorable" -

"Master, I have a clear shot on her" - Emiya said telepathically to Ritsuka.

"Take it" - the Master answered.

The red bowman did as he was told, an arrow flew from his bow towards the Goddess, but she destroyed it with a flash of lightning.

"You'll pay for that insolence" -

"You'd wish. Japanese Faction, no mercy!" -

And thus, the battle began.