Rias' group managed to rescue their 'Bishop', Gasper, in a short amount of time and immediately returned only to find a Devil battling with Yoruichi.
"That's... Katarea Leviathan!" Rias exclaimed, "I see... So it's the Old Satan Faction who's behind this!"
But as they get close, they noticed that this isn't exactly a battle as Katerea couldn't even land a hit on Yoruichi who is only dodging her magics with a small margin, as if she knew what Katerea was about to do.
"This bitch!" Katerea muttered in frustration, 'Where the hell did this bitch come from!?... I'm not yet facing one of the leaders, but I guess I should stop holding back.'
Reaching a decision, Katerea started laughing wildly, "Ahahaha! You're strong! But still not on my level! Die!" From her back, multiple shadows in the form of snakes emerge from her back and launch towards Yoruichi attempting to devour her.
The four leaders furrowed their brows after seeing this and Sirzechs muttered, "So this is Ophis' power... Just get that and she's already on the level of the current Devil Kings. If used properly, she'll be as powerful as the previous Devil Kings."
Already expecting this, Yoruichi immediately released her Reiatsu-Ki, "Shunkou!"
Just like when she previously used this technique at Gremory-Phenex Rating Game, a pair of wings made out of lightning manifested behind her.
Making use of the concentrated lightning behind her, Yoruichi pointed both of her hands onto Katerea unleashed her attack towards the snake, meeting them head-on, "Shunshin Raijin (Flashing Lightning God)!" A beam of lightning went through the snakes and directly hit Katerea without being able to react much.
"GAAAH!?" Katerea shouted in pain as most of her body was burnt. She's only alive after she subconsciously directed some of the snakes in the path of Yoruichi's attack. Wheezing in pain, Katerea looked at Yoruichi in terror, "W-What are you!?"
Even the four leaders and Grayfia were asking the same question in their minds. That attack just now, although it does not look very impressive of grand, it still tore threw Ophis' snake with ease and that kind of strength is almost coming close to a Devil King.
"That form... This intensity... And examining it further, it's not magic but it's similar to Touki (Fighting Spirit). So we're still underestimating them... Just how much are they still hiding? I doubt that's the extent of her powers." Azazel muttered and the rest who heard him could only stay silent and contemplate on their own, but they all reached a certain conclusion that just the two of them, in terms of pure fighting prowess, could go against some small Mythical Factions in the world and the fact that they are too dangerous especially when they don't know their motives.
From afar, Akeno is watching and admiring how Yoruichi 'elegantly' controls her lightning with ease and thought, 'Should I accept her offer back then?'
"Does that really matter now? We're trying to kill each other, right? Let's just focus on that." Yoruichi just smiled at her, 'Even though she's burnt, it's not much of an injury... Her endurance is way beyond what I expected. Is this her own power or Ophis?'
Katerea gritted her teeth, 'She's at Devil King level and the fact that she's here means that she's also part of the Peace Treaty...' Her Demonic power then flared up along with Ophis' snake using everything she has, 'The four leaders are eyeing me now, the plan of using the Forbidden Balor View already failed and I can't expect anything from Vali as he already did his job of creating a gate inside the barrier so there not much chance of me getting out of here alive. I should at least bring her down with me and the faction behind this bitch should retaliate against the Three Faction for not protecting her properly!'
Reaching a decision, she flew, with the fastest speed she can manage, towards Yoruichi and let the snakes lunge at Yoruichi again. In response, Yoruichi just materializes a spear made out of lightning and hacked away at the snakes.
Katerea used this chance to get closer but Yoruichi won't allow her and threw the spear towards her chest. Yoruichi expects that she would dodge but her crazed smile got even crazier and she didn't do anything about the spear, resulting in it piercing a big hole in her just and surprising Yoruichi, creating a small opening for Katerea.
Both of Katerea arms split into many tentacles and coiled around Yoruichi. Yoruichi tried increasing the output of her Shunkou but it still couldn't destroy the tentacles, "It's no use trying to get away! These arms of mine can't be severed!" Katerea body then started to bloat and red veins emerged from her skin.
"Trying to take me down with you?" It's then Yoruichi's turn to sport a crazed smile, "I'm sorry, but I already promised to die with someone else."
'Uhmm... Dear leaders, I advise that you strengthen the barrier around the school... No, I strongly suggest that you do it if you don't want any damage to reach the world outside! That idiot will overdo it, I guarantee it!' The leaders then received a telepathic message and the voice they heard inside their heads was unmistakably Kisuke's.
The first one to react is Azazel as he shouted to the other three, "This is my first time hearing him actually panic! Let's do it! I also have a bad feeling coming from that woman!" Raising his arms up, he sent his Holy Power to the barrier to strengthen it.
The other three didn't say anything else as they also felt something bad coming from Yoruichi and immediately supported Azazel's actions. The young Devils and Angel have a confused expression as they watch their superiors try to strengthen the barrier which is already strong, to begin with. Even if a bunch of Ultimate-Class beings started a war here, they wouldn't be able to damage it easily unless they specifically target it.
The lightning wings behind Yoruichi suddenly disappeared and the lightning emitted from Yoruichi's back creates a circle of electrical energy in the shape of Raijin's drums behind her, "Shunkou! Raijin Senkei! (Flash War Cry! Thunder God War Form!)
Yoruichi then unleashed a giant column of concentrated lightning energy engulfing Katerea and 10 meters around her. Katerea couldn't even scream as she's directly vaporized along with her surroundings, leaving only the severed arms that are around Yoruichi which also turned into dust a few seconds later.
On the ground, a deep chasm was created and although the leaders strengthened the barrier, that gigantic lightning just now still punched a hole through it. Thankfully, the damage is only that and didn't affect the Human World that much.
"Hey... Serafall... How much time do you need to charge an attack with the same kind of intensity?" Azazel asked as he stares at the unbelievable scene.
"O-our abilities are of different attributes so I can't do that kind of destruction in an instant, but I would probably need a few minutes of uninterrupted casting to achieve the same destruction. Although I might be capable of the same damage to the surroundings, that's not really a good measure of power." Serafall answered.
"...You're right... I'm sorry for asking something silly. I just really can't comprehend how she was able to unleash something like that in an instant."
"If it's pure destruction, then Sirzechs-chan is capable of that... But he's also in a different dimension from the normal Devil Kings..."