Koneko learned something.
Not every day she worked for Naruto was sex with monsters, there were many potions he had her test where the results were just her hair growing longer or mundane stuff. If anything, her having sex with a monster was 1 out of every 7 experiments that Naruto did, and more often than not it was because he didn't have anything else for her to test out. Actually, it was super disappointing for her to learn that most of his experiences with monsters didn't succeed right away, and she was seeing just how much hard work that he put into everything he did.
It was amazing, but disappointing for her sexual urges.
Right now she was little more than an assistant to help Gasper Vladi calm down during his examination with Naruto.
"So, you're a Daywalker Dhampire, half human and half vampire, turned devil who also has a Time Stopping Sacred Gear... yeah, I can do something about this." Naruto stated to Rias and Gasper easily enough. She had brought him to him, just like he had asked, while the rest of her peerage, minus Koneko, trained themselves to exhaustion on his Steel Tipped Tentacle monster.
Not a sex monster, but a battle monster.
"Really!?" Gasper seemed excited, but turned red and became shy, averting his eyes from Naruto.
"Your issue is confidence and you fear your own power, and you're afraid of what you are, well there are multiple things I can do. I can make a potion that can make you not afraid for a limited time so you can get your Sacred Gear under control, or I can remove your Sacred Gear safely from you so you can just focus on your Vampire side." Naruto explained at least 2 of the routes they could take with curing his issues.
Rias raised a hand.
"Removing a Sacred Gear-"
"Oh, I already took his Sacred Gear before he entered this building. This apartment building is surrounded by a Barrier Tentacle-" Naruto stated as a tentacle started to grow out of the walls, and it had an eye on it. The eye looked towards Koneko and she stopped in Time, her body no longer moving.
Naruto didn't want Sacred Gear users ruining his work, so he created a Barrier Tentacle that had the ability to steal Sacred Gears from anything that entered the barrier, for as long as they were in the barrier. The Sacred Gear was still technically connected to the user's soul, it was just no longer inside of their body since the Tentacle was using it instead of them.
"Remove" might be the wrong word.
"When did you make that, how did you make that?" Rias asked, since it had only been a few days since Naruto started to help her.
That was amazing progresss for such a short time!
"Eh? Well, you have 3 Sacred Gear users in your peerage, so I figured this much was at least needed to help them train. Using Kiba and Issei's DNA that I borrowed, I created this, though it doesn't work without the Barrier which takes some setting up." Naruto stated rather simply.
Gasper was looking at him with widened eyes filled with respect.
He looked at Rias, and he tried to activated his Sacred Gear, but he found that he couldn't activate it even when he wanted to. His eyes lit up in happiness and he looked towards Naruto, and he bowed, hands on his knees.
"Thank you, please don't give it back!"
"... Once you leave the barrier, you will get it back, but if you want I could transform it into a Monster that you can command instead. That way it follows your verbal orders-"
"Does that mean you can turn his Sacred Gear into a muscular man-type monster that can freeze time, and if he were to make the verbal order for the time freeze by 'The World' you could do that!" Rias realized something amazing rather quickly. She realized that if he removed the Sacred Gear from Gasper's body, and could transform it, he could create something that she had only dreamed of. "Gasper, you need to start practicing saying Muda Muda Muda really fast!" Rias turned to Gasper.
...
Naruto put a hand on her shoulder and smiled.
"I'm not doing that, I'm taking this very serious, I'm not making a damn Jojo reference out of this. Gasper is important to my research on both Traps and Vampire biology, so I'm not going to do anything that could result in him getting hurt." Naruto forced a very unpleasant smile on his face. Rias gulped when she realized she had showed her anime obsession, and that she had all eyes in the room on her.
Asia came into the room from the front door.
"I'm back, I'm going to start..." Asia laid eyes on Gasper. "... I hope I have enough to make everything." Asia thought on all of the stuff she bought. Naruto had told her that they would be getting somebody living with them, but she didn't expect it to be such a cute girl.
A cute girl.
Naruto saw her eyes, and her snickered to himself.
"It's true then... if I let you research me, I won't need to be afraid anymore?" Gasper asked in a low voice. He had hope in his eyes still, but it would seem his confidence in himself was making him lose hope. Rias wrapped an arm around him, but Naruto waved her off. She looked a little put off that he was preventing her from comforting Gasper.
"That depends on how much you're willing to go through, but I can help you go through it. At the very least, for as long as you stay here you won't need to worry about your Sacred Gear, and there are multiple solutions for your problems... if you want, I can research a way to take away your Vampire side... that can also solve your problem." Naruto offered that solution as well. Since Vampires could reproduce by biting humans on the full moon, that meant that they had a biological or magical function to their bodies.
It could work in reverse.
If he could locate that biological/magical function, and reverse it, then he could bite Gasper on the New Moon and erase the Vampire from his body, leaving only the human parts behind.
"That's impossible, no natural born vampire has ever become human before." Rias stated to Naruto.
Naruto plucked one of Rias' hair quickly.
"OW?!"
Naruto got his potion making supplies ready and he started to work on a potion, using Rias as a base.
It took 30 minutes, but Naruto held a bubbling black potion out to her.
"This potion will transform strip any half-devil that drinks it of their devil side, and if a pure-blooded devil drinks it, it will seal all of their magical abilities and make them human for as long as the potion is in their system... go ahead and test it." Naruto offered her the potion. He had already researched her devil biology thanks to his creating her Anti-Monster, so he had a pretty good handle on her biology and how to make a potion to work against it. "Go ahead, test my skills with potions. Remember, you have a method to transform a human into a devil, there is no way it is impossible for me to do the opposite... drink it." Naruto stated to Rias.
Rias gulped.
"... How long will it... stay in my system?" Rias asked as she picked the potion up.
"About 29 hours, give or take a few minutes. Your DNA is magical at it's core, meaning that you're actually a lot less complicated than a human to understand. I admit, it will take a lot of effort to take away Gasper's vampire side, if he wants me to do that." Naruto looked back to Gasper.
Gasper froze for a moment.
"... I would... I'll keep my Vampire side... please, just help me get my power under control... please make a monster out of my Sacred Gear." Gasper pleaded with Naruto, and Naruto extended his hand out to Gasper.
Gasper gulped.
Rias looked at the bubbling black potion, and she shivered when she had a horrifying thought go through her mind. That horrifying thought also gave her more ideas on ways that she could use this potion.
Gasper took Naruto's hand.
"Hey... can I have this-"
"Pay me money for it, that potion isn't part of the deal. You want that potion, then pay me... 300,000 yen and let me study your Evil Pieces for awhile." Naruto made a business offer for her.
The potion's ingredients were worth about 900 yen when you added them all up together.
He was WAY overcharging her.
"Very well, I can agree to that."
Well fuck, he didn't expect her to actually agree to that price.
He was not going to underestimate how rich this girl was in the future, and set his prices even higher for her. He was going to hold a grudge against her for how hard she was working him, and for as much effort as she was milking from him, she was going to get an equal amount of money milked from her.
"Koneko is still frozen by the way." Rias pointed out.
Naruto looked at Koneko, frozen in time.
He grinned and took out a marker.