Dealing with the devil

While Mateus is dealing with the entire situation with Rias and Sona, in a certain place, to be precise, in the underworld, commotion is unfolding. The reason? Needless to say, it's obvious that it's because of Mateus.

The city of Kuoh is governed by devils; it holds extreme importance due to its location and other factors. For the devil leaders, considering losing this city or letting a disaster happen is very difficult.

But there's another factor that makes this city important to the Great Satans. The reason is that the sisters of two of them take care of the city. And being siscons, they worry more than usual about anything related to this city and their sisters.

Because of this, two of the Great Satans are quickly heading to the location where Mateus released his magical power.

But not only Serafall Leviathan and Sirzechs Lucifer have set out for the location, but also a beautiful maid with gray hair has also departed.

— — —

In Rias' school club room, Mateus has just mentioned that he doesn't mind waiting for a while, so Rias stands up, indicating that she will contact her brother.

However, before this occurs, Mateus, with his heightened senses, perceives three extremely strong auras approaching his location through teleportation magic.

Quickly preparing himself mentally for whatever comes out of this conversation, Mateus watches as a magical circle forms on the ground, capturing everyone's attention in the room. Rias, who was about to contact her brother, puts that on hold and decides to wait for the individuals emerging from the magical circle.

After the three devils arrive in the room, two of them simply ignore the man who caused all the commotion and head directly to their respective sisters.

"Ria! Are you okay?!"

"So-tan! Are you okay?!"

Watching the show of two siscons unfold before him, Mateus finds it all quite amusing and happily enjoys the free entertainment.

After the brief spectacle concludes and numerous explanations are provided by Rias and Sona, the two Great Satans and the gray-haired maid finally turn their attention to Mateus, deciding to address whatever it is he wants.

"Let's begin properly then. My name is Mateus Santos, just an ordinary mage. It's a pleasure to meet you, Lucifer and Leviathan." Starting the conversation on a positive note, Mateus introduces himself and addresses them using their respective underworld titles.

"I am Sirzechs Lucifer, and beside me is Serafall Leviathan. As you may already know, I am the leader of the underworld. So, what did you want to discuss directly with us?" Introducing themselves and presenting the person next to him, Sirzechs inquires about Mateus's intentions, even though he already has an idea based on the brief conversation he had with Rias.

"Like I discussed with your sister, what I simply want to know is whether your faction wants to be my enemy or not. Some time ago, one of your kind attempted to assassinate me while I slept." Clarifying his inquiry, Mateus directly questions the leader. His true intention is merely to establish a relationship of peace and collaboration with the devils, similar to what he has with the angels. He doesn't seek enemies, but if that's the case, he'll have to eliminate those who claim to be his foes.

Listening to Mateus, Sirzechs understands his intentions. He begins to speak, "Actually, we never intended to be your enemies. In fact, we wanted to recruit you into our faction. But an unfortunate incident made it seem like we wanted the opposite. Now that you know our true intentions, I extend this invitation to you. Would you like to join our faction?"

"I refuse." Mateus had missed saying that. In reality, Mateus has no desire to become a demon. If he did, he could find some kind of magic to accomplish it, but as he has no such inclination, there's no need to worry.

However, Mateus understands the importance of adding more to his words, or he might be misunderstood as someone rejecting any collaboration with the devils. Adding to his statement, Mateus says, "I refuse to become a demon, but I am not opposed to the idea of being on good terms and having a peaceful relationship, helping each other out. What do you think, Sirzechs Lucifer?"

Mateus proposes what he desired from the beginning – a relationship similar to the one he offered to the angels. Now it's up to the devils to accept being at peace with one of, if not the, strongest being in this universe.

Even though it's not exactly what Sirzechs had in mind, a relationship of peace and mutual assistance seems like a good proposal to him. He looks at Serafall by his side, and with an exchange of glances, they appear to reach a conclusion.

"For us, that's fine. This seems to be the best type of relationship we can have." Accepting the offer, Mateus sees that he has fulfilled his purpose here. After achieving his goal, Mateus adds, "If you need my help and I can and am available, I'll assist with all my capacity. So, I hope that's reciprocal, okay?" Expressing once again what he expects, the devils agree, and Mateus prepares to leave.

"It seems I've resolved what I needed to do here. Shall we go, Ophis?" Getting ready to leave, Mateus calls Ophis, who quickly gets up and stands by his side. However, this name doesn't go unnoticed in front of the new people present in the room.

"Ophis? The Infinite Dragon God?" The reaction is, once again, as expected. Mateus realizes his mistake and quickly says, "It seems I forgot to introduce her to you. Yes, she is Ophis, the same one you know, and also my little sister." Introducing Ophis, everyone is incredulous not because she is a Dragon God but because she is Mateus's little sister.

Without giving time for reactions or further explanations, Mateus bids farewell.

"It's all, folks. Until next time." Holding Ophis's hand, Mateus activates his teleportation and returns to his home. Once again, Mateus surprises; he teleported without the use of magic circles.

After Mateus's departure, the room falls into silence for a moment until Grayfia breaks the silence, asking her husband, "Did you manage to gauge his strength?" It's a question that Sirzechs typically answers easily, but this time he says, "I can't say anything about him. It's as if he were just an ordinary human in front of me. But he's strong, very strong. His magical aura is capable of stirring the world. He also claims that Ophis is his little sister, so I believe he is very powerful."

"But powerful to what extent?" Rias asks.

"I can't tell how." With these words, the room falls into complete silence. The strongest demon can't assess someone's strength? This is more than enough reason for surprise and the demonstrated silence.

— — —

Unaware of the situation that unfolded with the demons, Mateus is at home and can finally relax.

"That was a long day." Feeling exhausted, Mateus decides he'll take a nice bath and then head to sleep.

He informs Ophis, "I'm going to bathe now; if you want, you can go to sleep earlier." Saying this, Mateus can't help but think. He's never seen Ophis take a bath, that is if she needs one. Still, he finds it strange but chooses not to comment on anything.

Almost as if hearing Mateus's thoughts, Ophis says, "Can I take a bath with you?"

"…" These words just spoken by Ophis leave Mateus perplexed.

Using his accelerated thinking, Mateus has an idea. Since he met Ophis, it was as if she indeed had a gender. So, to clear his doubts, he decides to create a new skill.

[The God Eye skill has been created.]

With this skill, Mateus can see through everything, even lies. Trying to look at Ophis's status, Mateus sees the following

~

Ophis

Infinite Dragon God

Age: ???

Gender: Female.

Mateus could look for more things like abilities, but he only needed confirmation. In this world, Ophis has a gender. So, Mateus begins to wonder, 'Do all dragons in this world also have gender?' If so, some of them better prepare, as Mateus will undoubtedly capture some, if you catch my drift.

Exiting his thoughts and returning to the normal world, Mateus simply looks at Ophis and says, "Sure, why not?"

Then, preparing to enter the bathroom, Mateus undresses, and Ophis does the same. Entering the bathroom, Mateus has more thoughts. 'Does Ophis know how to take a bath?' It might seem like a silly question, but for Mateus, it's valid. The person in question has almost no common sense, so Mateus judges that she might not know how to take a bath.

So, Mateus slowly teaches and helps Ophis to scrub and clean herself.

Pouring water and rinsing off the soap from Ophis, Mateus finishes cleaning her and says, "Get into the tub first and wait for me there; I'll just finish washing up." Doing as instructed, Ophis waits for Mateus, who quickly finishes what he was doing and gets into the tub.

Relaxing in the tub, Mateus feels all the stress fading away. Moments like these are wonderful and make Mateus reflect that peace is always the best thing.

Enjoying Ophis's company, both of them indulge in a good bath.

After the bath and before going to sleep, Mateus once again finds himself in thoughts. 'I haven't seen the description of any skill that reached maximum mastery; what could it be like?' Mateus quickly asks his system to provide the description of a skill.

[Water Magic Mastery - 10. With this level of mastery, your magic is unparalleled, surpassing gods of this element. You and water are one. There is no one who manipulates water better than you.]

Seeing this ridiculous description, Mateus realizes that he is now the strongest being in the universe. Without more or less, Mateus simply accepts this fact and more. He starts thinking about becoming even more powerful.

'Since I'm already this strong, wouldn't it make a difference if I get even stronger, right?'

—*—*—

Tell me about potential women for the harem. It can be from the works presented so far, or any others, including other worlds or games like Genshin Impact or Honkai.