Conclusion

Regina's PoV

The House of Phenex is famous for their immortality with it they are almost unbeatable, however there is still a limit to it and there are many ways around it.

The first one is to overwhelm them with enough damage at once that their regeneration cannot handle. Eventually they would tire out as their ability is extremely mentally taxing.

The second is similar to first. It is simple really. You just need to use an attack where it kills them in a single round where nothing of their body would remain.

The third is using something to counteract the regeneration. If something damages them at the same speed they regenerate it would effectively counteract their healing or at the very least slow it down, but this usually depends on the Phenex you are fighting as the stronger ones have a faster regeneration speed.

Of course you could also seal their ability using a special power like Belial's [Worthless] or seal the Phenex themself to buy enough time to prepare an attack that can kill them in one hit.

Another are mental and soul attacks. Their power only affects the physical body. Although rare few beings are capable using it, few beings are capable of resistance. Those who have a strong mind can resist it though it usually depends on how strong the mental attack is.

Those that attack the soul are also extremely effective even to the most powerful of beings as the soul is extremely vulnerable. Of course granted that you have a technique that is capable of harming the soul in the first place.

However most soul attacks are dangerous as you would use your own soul to power up the attack and doing so would damage it in the unlikely event that they can defend against them or counters it. It also makes your soul vulnerable to attacks.

As for why im explaining this, its because Issei used one of the counters, that I told him earlier.

Before coming here at Issei's house he told me that he wanted something to counter the Phenex's immortality. So I explained the different ways to overcome it, thinking deeply things he thought of was holy water. Which is actually viable as the Phenex Clan are still devils unlike the original Phoenix.

The problem is how will Issei use it. Issei himself is still a devil and its extremely lethal to devils like him. However what he showed, shocked us. He said that he gave his arm to the Red Dragon Emperor for him to use his balance breaker for a limited time, and the duration would only be 10 seconds.

However since he gave his arm to the Red Dragon Emperor, it is technically a dragon's arm not a devil so he is now able to use it.

Looking at the scene right now he succeeded and Riser's regeneration is being slowed down by the holy water. He also had a cross in his hand as he punched Riser's face.

[BOOST!]

As Riser's face got hit, Issei also transfered power to the holy water.

"Boosted gear gift!"

[TRANSFER!]

Riser who was hit by this cried out in pain

"Ah! Damn you!"

Issei just kept hitting him with the cross on his left hand. Riser tried to retaliate but Issei easily dodged the attacks using [Foresight] and punched Riser once more.

"Fall down already!!" He yelled out as he swung his left hand.

Hitting one more time he sent Riser back a few distance away from him. Riser who was sent backwards fell to the ground and didn't seem to be recovering. It appears he lost consciousness.

Issei seeing this let out a sigh.

Looking at his victory I let out a smile and looked towards Sirzechs who seemed content with the result.

Feeling my gaze he looked at me and said, "You were right, He truly let us see an interesting match."

Rias then came towards Issei as her Father, Sirzechs and me walked towards them.

"Nice job." I said as I patted his head.

Hearing me Issei looked towards me as he hugs Rias and bowed his head.

"Thank you very much."

He then took out the magic-circle paper that he had and used the other side of it.

Light shined as a griffon appeared in front of it.

"Roar!"

The griffon who appeared roared as Issei looks towards me

"Its fine. I have my own ride go on ahead. I'll see you at school."

Hearing that he let out a smile and flew with Rias on the griffon.

A person from the Phenex house demanded an explanation and telling us to hand over Issei to them for the crime of trespassing on an event held by nobles.

Hearing this I was prepared to step in however Sirzechs held my shoulder and stepped forward.

"I do apologize for what happened and will give you an explanation. I will ask that we talk about it on a later date."

The man who I presumed to be the Phenex Head wanted to argue a bit more but eventually sighed and agreed for them to talk in a few days.

After discussing the date of the talks he went back to check on Riser.

"Will there be any problems?" I asked Sirzechs.

"Its fine, I'll deal with it. After all like you said I can only scheme to get what I want. Its the least I can do." He replied with a teasing tone.

"You..." I was gonna retort but just leave it at that and sighed.

"Rias' Peerage should be fine staying here right?" To which he nodded.

"I see... then if heres nothing else I'll head back. I'll talk to you again later properly as this situation isn't the best of first meetings.

I'm still allowed to come here right?" I asked him since I technically helped crash a pure blood noble's wedding.

"Of course." He then gave me a badge like object.

"What is this?" I asked at him curiously. It had a spell symbol that belonged to the house of Gremory however below was a name written, 'Sirzechs Lucifer'.

"Its an authorization of sorts. We cant have humans coming in to the devil's area just like that. Some guards would probably apprehend you, but with that you could visit without problems." He explained.

I thought for a bit and gave him a device that looks similar to a phone.

"Take it, its a communications tool developed by [Regulus Dominion]. Using it you can contact me. Just pour demonic energy and find my name there to use it." I told him.

Having a connection with someone influential in the underworld especially a Demon King would be really useful.

I then suddenly remembered something. I never really introduced myself have I? He only knows me as the [Golden Princess].

"Now that I think about it we never really properly introduced our selves." He said to me remembering. He would need to know my name to contact me which caused him to remember.

My name is the only one there as thats my spare device. Before giving it to him I inputted my name there for him to contact me.

"Ah right, might be a bit late but...

I'm Regina Gilgamesh-Regulus, supreme leader of the [Regulus Dominion]." I said with a noble's bow for girls as I held the tip of my skirt while putting one of my right foot at the back of the other.

From a young age we were taught such mannerisms by our mother at a young age as the Arclight are still nobles on the surface and she wanted us to learn of a noble's behavior. Although honestly I found it a waste of time and only used them in formal events which are very few.

Looking back at it now she probably had a faint hope and dreams that we would be accepted by the house, though in the end it was them who pushed us into despair.

I introduced myself including my position. Although I didn't need to give it, I find it appropriate so he knows who he is dealing with and the authority I hold within the organization. Maybe in the future we could be allies with a treaty.

Hearing my title he was a bit shock as few people in the world know that I am the organization's leader. He regained his bearing and introduced himself.

"I am Sirzechs Lucifer who holds the title of Demon King Lucifer in the underworld nice to meet you."

"Likewise." I replied as we shook hands.

"Do you need a ride home? I could prepare a griffon if you want." He asked me

I was planning on summoning something from my treasury however riding a Griffon does sound interesting as I never rode one before.

"I'll take you up on your offer." He then gave me a paper similar to Issei's paper.

"You can use that to summon and control the Griffon. You can also keep it as a gift from me." He said as I looked at the paper.

I nodded at him and summoned a griffon.

"Well see you." I said as I gave out a light smile as I take off. He nodded and waved a bit.