After Subaru's heated conversation with the Crusch Camp, Subaru and Rem went back to the inn they were staying at, he and Rem decided to call it a night and try again tomorrow but while they slept Subaru had this weird dream where he saw this white haired kid with a black broad sword and the same book that became apart of his body.

This boy was using the swords to negate magic like it was nothing, but what shocked Subaru the most was his transformation, part of his hair was black and he had a horn coming out of the  black side and he had black energy swirling around him the same black energy that he had swirling around him, this boy also had a black mark on one of his eyes and a big black wing on his black side.       

After that Subaru kept seeing more of these dreams where that same boy was fighting a lot of other people and using the same form from before, it turns out he called the demonic transformation "Black Mode" as he was using a different sword it was a lot smaller than the broad sword and he was able to counter attacks a lot faster with it, he also saw a scene where he made the broad sword bigger than usual as it sliced a whole building in half.

For Subaru this felt nothing like a dream, it felt like he was there but not there at the same time. It felt like he was watching this boys memories or having visions, whatever it was it was giving Subaru a lot of information about his new power, apparently this power was called "Anti Magic". He learned that it's a unique form of energy allows the user to nullify other forms of magic. It can be used to defend against attack spells, break through defensive spells, and nullify pre-placed magical afflictions, such as curses and traps. Only someone without magic could use it.

 Subaru woke up soon after, it was still in the middle of the night but he wanted to learn how to use his anti magic as soon as possible so he snuck out the room being careful not to wake Rem up. After he left he went straight for the forest to train there he would train until it was morning.

When he came back, Rem rushed up to him asking him where he's been. "Subaru-kun! Rem has been looking everywhere for you where have you been!?" Obviously she was extremely worried for him so he answered honestly to ease her worries. 

"No worries Rem, I was just out training."

"Training?"

"Yeah I was training to clear my mind, I just couldn't sleep."

Rem wanted to ask more but Subaru wanted to get more help to defeat the cult as soon as possible, Subaru sent Rem's to the knights brigade while he went to go look for the other royal candidates and ask for help. Subaru went to Priscilla for help but that exchange broke down when she asked him to lick her feet. He almost did in fact, and was sent several feet back by a powerful kick in response, only for her to raise him to her face filled with anger and disgust.

"What you have is neither loyalty or faithfulness! It is filthier than that. It's a dog's existence or the greed of a pig. A lazy pig that wants, desires and begs for all! It is the most unsightly greed of all!"

"Uhk."

"Even if you do drive of the Witch's Cult, I shall destroy the camp you belong to and anyone involved with it with my bare hands. All for harboring such a despicable beast!"

"Ah!"

"Take some pride in this...the destruction of the Emilia Camp will be because of your actions."

While she said this Subaru got pissed and some of his anti magic energy leaked out, Priscilla noticed it was eliminating the mana in the air and quickly threw him across the room. But when she looked at him he was glaring at her with his red demonic eyes now red with slits. Priscilla quickly called Al to take him out. Not even Al could hear Subaru's muttering as he was saying...

"You'll pay for this."

As Subaru was being escorted out, Priscilla noticed his tail as she saw him still glaring at her. As soon as he was gone Priscilla thought back to when Subaru was eliminating the mana in the air as if it was nothing. "Just what was that? There was no mana interference in the atmosphere yet he was eliminating it...just what is he!?" Priscilla angrily thought as she looked at the very same spot she man handled him not so long ago as she remembered that demonic glare. It frustrated her.

"That damn stuck-up bitch! she's forgetting I'm the one who saved her life when we first met!" 

Subaru angrily thought as he bit his bottom lip in frustration...

"Wow! Hey onii-san, are you okay? Your lip is bleeding are you alright?"

"Huh? N-Nothing to worry about kid, I'm fine."

"Well, Mimi sometimes bites herself when she eats reeeeelly fast! Want me to heal you?"

No, that's fine thanks.

Subaru found himself speaking to a little beast human, a small orange haired cat girl, he deduced her name was Mimi.

He thought she was just a curious, nice girl. But he tried to brush her off, his time was limited and he was still pissed of so-

"Hey Mimi. Don't go causing mischief for other people."

"...Anastasia Hoshin."

"Oh, well if it isn't you! Hi Natsuki-kun, feeling better?"

"More or less."

Still, Subaru scanned the area in case another person he hated was nearby.

"Relax Natsuki-kun. Julius is on other business he's not here. 

"...That so?"

And so Subaru asked an audience with her, and she obliged...but as they walked Subaru furrowed his brows.

"Priscilla. An uptight woman with no respect. Al. We may be from the same world but he's 'grade a' useless in this situation."  

He clicked his tongue. 

"Pisses me off"

Meeting in a casual eatery, they sat to discuss some matters pertaining Subaru's predicament. And so Anastasia did him a favor...

"I've written down the location of a shop that should still have a dragon carriage available. Here's my signature, really it's all you need Natsuki-kun."

"So high and mighty about it huh?"

"Hey when the opportunity arises right?" 

He hesitantly took the note but Anastasia insisted on chatting more and she was curious about him she noticed his tail, she also wanted to know his origin so she asked...

"Say Natsuki-san where are you from?"

"Like my birth place?"

"Yeah, tell me."

"Well, hope you believe me. I'm from beyond the Great Waterfall, from a place called Japan. Far east just before the nation of America. Well, maybe some small islands from between that, but I don't recall their names."

"...Beyond the Great Waterfall. Ok and about your tail last time I saw you never had a tail and your body wasn't that muscular either, what happened to you?"

Subaru didn't know how to answer that question, he didn't want to tell anyone he rarely knew especially someone like Anastasia. Last time he checked she said she was a very greedy girl so giving information about what he knew about his new power and how he got it to her was definitely a big no no so he answered with this... 

"Sorry but I'd like to keep that information private."

''I see.''

After a few more minutes of small talk...

"So Karsten has been purchasing all the city's iron supply huh? Hm, so that's why Russell Fellow was there yesterday."

"OH? Russell Fellow. Good find, thanks Natsuki-kun. That should be some useful info."

Now, Subaru realized that her light blue eyes saw past him. Like a con artist watching a fool fall into their grasp.

"...You set me up."

"You got into a shouting match with Crusch last night and went your own separate ways. I figured now would be the golden opportunity to read you and your emotions, you seem easy that way."

This trickery and her nonchalant made his blood and his blood boil and his heart race to a fever pitch. 

"Sorry Natsuki-kun, but this is the way of business." 

"How could you mistake my intentions Anastasia? I'm trying to do the right thing! How is it that you could-"

"-Could what?"

"Ah.''

"Let me say something. Your worth is decided by what you have done, and you have done nothing for me to show any value Natsuki-kun. And furthermore, your righteous path should be backed up by concrete actions if you want people to believe in them...I don't see that in you." 

All the deaths. Suffering. Anguish. Scars no one else could see, she just...ridiculed them, bashed them, and called them nothing important.

At this point Subaru had half a mind to grab a chair and beat her to death with it.

Mimi sensed this, pointing her staff at him, making the young man back up a step.

"Onii-san, back away from my lady, otherwise the super strong Mimi will have to hurt ya!"

"Thank you Mimi, but don't worry. Natsuki-kun here can't do anythin-"

That's when she noticed the mana in the atmosphere was being wiped out like it was nothing but there was not mana interference. She looked over to the source and to her and Mimi's surprise it was Subaru doing it. The pressure was so much that it was making it hard to breath.

"W-What's going on he had no power at the castle... so how is he...?" 

And when Anastasia looked into his eyes it slightly terrified her his eyes were red and demonic with his pupils as slits. If looks could kill it would kill her on the spot, even Mimi was terrified.

After awhile Subaru calmed down and the black aura died down, Anastasia and Mimi regained their composure and when they looked at Subaru again his eyes didn't change they remained the same.

Subaru was beyond pissed, he wanted nothing more than to bash both their skulls in but her knew he couldn't do that.

Knowing that bastard Julius served her, he should have expected she was the worst.

No, they all were. All the participants besides Felt and Emilia were all utter scumbags that were allowing innocent people to die. 

Crusch had  no pity for him.

Priscilla actively declared open hostility towards them. 

And now Anastasia only helped a smidge for the purpose of personal gain.

Rotten.

They were rotten.

This entire country was rotten.

Filthy, diseased .

Allowing pure innocent children to be brutally slaughtered.

Hardworking people to be violated.

Everything was wrong

HE HATED IT.

Though Anastasia was still on guard by the sudden display she saw, she still left before saying this...

"Bye then Natsuki-kun. Pleasure doing business with you. 

"..."

"All right then, lets go!

With that the entire mercenary group left with Anastasia and Mimi all the while Subaru just stood there not acknowledging anyone there until they were all gone was when he slammed his fist on the table making a few cracks on it.  

"DAMN IT!"

Rem came and the first thing she saw was Subaru slam his fist on the table. As she quickly ran up to him she looked at his eyes. They were the same as before.

"S-Subaru-kun?"

Subaru heard Rem and quickly came back to his senses as she looked up at her. She was giving him a worried expression. 

"Subaru-kun, were you able to find anybody to help?''

"No not one bit, she set me up. Damn her!"

In the end Subaru and Rem couldn't find anyone to help them defeat the Witch's Cult. So they went to go look for the store Anastasia mentioned, once they did that they would be on their way back to the Roswaal Estate and stop the Witch Cult.