The moment the real Yuna cut off Isobu's head, she and her ice clone switched positions, and seconds later, the seal that Yuna put on Isobu's body while his limbs were restrained by her chains was activated.
Instead of Isobu's chakra dissipating after getting "killed", all of it started to slowly flow towards Yuna's main body. Unlike how it was with Kurama, Yuna didn't mix any of her chakra with Isobu's which meant that he could leave Yuna's body without any consequences for her or Isobu.
After a short moment, Isobu's body had completely vanished and the only thing left behind was the unmoving body of the current Mizukage. Yuna wasn't completely certain whether she was responsible for his death or not, but didn't care too much about it either way.
The moment Isobu's head landed on the ground and Yagura's corpse was revealed, the rebel army went into an uproar.
"Incredible! She actually killed the fourth Mizukage!"
"Who even is that? I have never seen her in Kirigakure."
"That hair color…Isn't she the head of the Uzumaki clan?"
"The Uzumaki clan? Aren't they from Konoha? Why is she here?"
While the rebels were excited about Yagura's defeat, Kirigakure's forces had pretty much the opposite reaction.
"Impossible! Mizukage-sama was killed!?"
"What are we supposed to do now?"
"Who is she? Is she really part of the rebels?"
Hearing the uproar happening on both sides of the battlefield, a smirk appeared on Yuna's face as her gaze slowly wandered over Kirigakure's forces. Every time she met somebody's gaze, the person would immediately look away in fear of provoking her.
Yuna pondered for a moment about what was the best choice to make and quickly came to a conclusion. She started speaking with an indifferent voice, that seemed to echo over the whole battlefield despite not being particularly loud.
"Oh? Seems like I got in the way of some kind of conflict? Well, I am done fighting the Sanbi and I am rather satisfied with the battle so you can continue to do whatever you were doing."
Hearing Yuna's indifferent comment about her indirectly killing the Mizukage, one of the strongest people in Kirigakure's army stepped forward with anger burning in his eyes.
"Is that why you killed our Mizukage!? You killed him only because you wanted to fight the Sanbi!? Aren't you from Konoha!? Do you think you can do whatever you want just because the last war ended in Konoha's favor!?"
A sneer of disdain appeared on Yuna's face as she looked at the Shinobi who just said that. The moment Yuna's eyes landed on him, he instinctively took a step back and averted his gaze. Just by Yuna looking at him, he felt a lot of pressure.
"I killed your Mizukage? Aren't you a little too delusional? Didn't you see how the Sanbi acted during my fight with it? It was acting just like a mindless beast. I don't know what exactly was done to your Mizukage, but I can guarantee you that he was already dead when he transformed, otherwise he wouldn't have fought like that."
[I thought you weren't sure whether you were responsible for his death or not?]
[Don't worry about that, Isobu. The moments where Yuna's thoughts and words match are rather rare.]
[I-Isn't that a bad thing?]
[Well, you get used to it.]
[T-that doesn't really answer my question, but I guess I shouldn't bother with that for now.]
'Ding! Individual, Kurama, has started the process of corrupting Individual, Isobu. Current progress: 5%.'
[HEY! That's my thing!]
[What was that!? Ding? Individual? Corruption? What is going on, Kurama!?]
'Haha, that was just a little payback.'
[Don't worry about it, Isobu. It's just a little…game…Yuna and I like to play. Hehe, that's right, just a little, innocent, game.]
[O-Okay.]
Although Isobu noticed the rather competitive and maybe slightly insane undertone in Kurama's voice, he decided not to bother with that for now. He did, however, decide for himself that he would get out of Yuna's body as fast as he possibly could.
Meanwhile, on the battlefield, Yuna's comment about the Mizukage caused a huge uproar in the ranks of both armies. During the fight itself, no one noticed anything weird, but now that it was over and everyone could think about it properly, they found out that it was indeed weird that the Sanbi was acting like a wild beast.
Killer B, the Jinchuuriki of Kumogakure, was well known for being able to fully transform into the Hachibi during combat and he doesn't act like a mindless beast while doing so. Although the shinobi of Kirigakure were missing a lot of information in regards to using a Bijuu's power, they still came up with their own conclusion without thinking too deeply about it. Rather than admitting that their Kage was inferior to someone from Kumo, they would rather swallow an explanation that pushed the blame on another factor. Especially, when Yuna gave them such a convenient way out by saying "I don't know what exactly was done to your Mizukage…", which implied that someone else was manipulating the situation.
"No way! Was someone really manipulating Mizukage-sama?"
"I found it weird that Mizukage-sama transformed at the start of the battle while he was still standing together with us. Wasn't that really dangerous?"
"That's right! Although his first two jutsu didn't hit us, it would have been really dangerous if he were to continue fighting that close to our troops!"
[Kurama, what is happening?]
[Mhh? What are you talking about, Isobu?]
[I mean this whole situation. I don't know much about human wars, but Yuna clearly interfered in one of them without being allowed to do so, so why is everyone suddenly talking about Yagura, instead?]
[Oh, this? Well, it is called diverting attention, and it is one of Yuna's favorite tricks. She doesn't want people to talk about her messing around in this war, so she puts their attention on something else and quickly leaves the location while everyone is too immersed in the new problem to notice her.]
[I see, that makes sense. I guess it was rather lucky that Yagura was controlled, otherwise, it would have been hard for Yuna to get out of this situation.]
[Haha, what are you saying Isobu? If he wasn't controlled, Yuna would have just lie…*cough*…err…uhh…f-found a way to compensate them for the trouble.]
Luckily for Kurama, Isobu was rather pure, so he didn't question Kurama's slip of the tongue and didn't ask what he was about to say either.
Yuna, meanwhile, chuckled a little at the duo's conversation and did exactly what Kurama said she would do. While everyone was fervently discussing whether the Mizukage was controlled or not, she stealthily vanished from the battlefield.