When the three of them joined Harakaze-sensei, their jutsus were already prepared.
Tetsu shouted, "Earth Release: Basic Platforms!"
Just then, the earth erupted beneath their feet, lifting them into the air.
Kannin cried "Water Release: Wild Water Wave!"
Drawing the subterranean water from beneath him, Kannin summoned a constant stream of water which supplemented the stream of water spewing from his mouth, with it, he scanned all around him, hoping to catch the missing-nin hiding in the darkness.
Warai released the Uchiha signature jutsu, "Fire Release: Great Fireball!" and spread it around too, trying to do what Kannin was doing, and also to see if the bright flame could light up the darkness.
Unfortunately the darkness summoned by the enemy's genjutsu persisted.
Tetsu asked Warai, "Warai, do your new eyes let you see through the darkness?"
Shin's eyebrow raised hearing Tetsu mention her 'new eyes,' and put together what must've happened while she was busy. While proud of her disciple, she couldn't congratulate her just yet.
Warai shouted back, "Kind of! I have to focus real hard, but when I do the darkness becomes more transparent."
Shin, finally addressing them since they joined the battle, said "Good. We're gonna rely on you to pick out where she's hiding. Tetsu, Kannin, keep up with the area control jutsu. She knows she can't take us on an even field, so we'll have to level it ourselves."
Saying this, she put her left hand up, and muttered 'I can't believe I'm having to do this. Sandaime is gonna have to pay me extra.' and spat out "Lightning Chakra Mode."
Suddenly, her body was enveloped by a thin layer of purplish chakra, which crackled and raised a field of static. Made her hair stand straight up, which would've made great sport for teasing, had the kids any time.
With Kannin and Tetsu clearing away large swathes of the enemy's range with broad attack jutsus, and Warai spotting the missing-nin through the darkness with her Sharingan, Shin was having a much better time fighting her. In fact, after about ten minutes, the darkness began to fade away, letting them see their enemy heaving and bloody in front of them.
Shin dispelled Lightning Chakra Mode as soon as the darkness cleared, since it was a huge drain on her reserves, and quickly ran to restrain the missing-nin. She had learned in the war that a judicious application of electricity could have a paralytic effect, and she used her lightning chakra to paralyze her hands, keeping her from using jutsu. She then tied her up to ensure she couldn't move.
When they had all recuperated, Shin stood before her and asked, "So who are you, and what are you doing here?"
The missing-nin grit her teeth and said, "I'm Yaburi Emiko, from Kumo."
"Yaburi, Yaburi, hmmmmmm" Shin seemed to be trying to recall information about her. "Oh right, you're that genjutsu specialist that deserted during the war. I wonder how much I can get selling you back to them!"
-
While they got to talking, the three amigos sat down together to finish their lunch properly--this time in silence. Not one of them had ever been in that kind of fight before, and it seemed to have press a solemnity about them.
Kannin was thinking back to their journey to Uzushiogakure, when he was so enamored by the darkness at night, and he was reevaluating his admiration for the inky blackness.
They sat there, eating, for a few minutes without a peep, only the hungry and childish smacking of lips--when suddenly Tetsu, with a devilish smile, peeped up, "Did any of you see sensei's hair just then?"
"Hair? It looked like a scared cat!
"Hahaha!"
With the tension broken, they all laughed at how silly their sensei's hair became due to the static. Shin glanced over to see what the ruckus was about, only to see three kids laughing and smiling with each other, and decided to leave it alone. Kids needed to be kids sometimes, especially after a battle like that.
-
It turned out that Emiko here defected during the war for pay reasons, and spent the next year or so bouncing around the small countries, until she came here where she used her singing genjutsu to lure ships into the giant whirlpools. They would crash and break apart, letting their cargo float to shore, which Emiko would either use or sell on the mainland.
"It still doesn't explain why the currents changed so much."
Shin shook her head, trying to come up with a reason, and eventually gave up. She turned back to Emiko and said, "I'm going to seal you into a scroll, and we'll figure out what to do with you once we get back to Konoha. No objections."
Not that Emiko could do anything about it; she was promptly sealing into a blank scroll. She then walked up to the kids, who were now deep into a conversation about their sensei's hair. Warai was gesturing with her hands above her head to emphasize the poofiness. And even with her new eyes, she couldn't see behind her head, and by the time Warai noticed Tetsu pointing behind her, it was too late.
Warai's face froze as she felt the evil aura emanating from her teacher. Through gritted teeth, Shin asked them, "So exactly what were we talking about over here?"
Warai got real sheepish and peeped out, "Oh...nothing...just, nothing. Y'know, talking about Kannin's sword."
"It seems like someone's feeling a little haughty after awakening their Sharingan! You wouldn't mind doubling our training now that you're so powerful now, huh?"
The stifled smiles on Tetsu and Kannin's faces dropped as well. They were already sore from the battle, even mentioning training made their spirits deflate to zero.
"At any rate, we should get moving. I know you're probably sore from battle, but if the smoke didn't attract attention, out fight definitely did. So gather your stuff."
"Yes sensei"
"Yes sensei"
"Yes sensei"