Saul caught back up with Hinata after they had finally defeated Gaara. Luckily it seemed like she had listened. She had not killed Gaara despite him showing his body as a big target for her to shoot at, atop Shukaku. It actually wasn't even him who found her, rather she saw him looking for her in the forest and met up with him. Around this time they heard a giant horn sound coming from somewhere inside the village.
"Saul-kun! We need to go back! The village!"
Saul shook his head.
"First, what's the situation with Naruto and the others?"
"They're fine, Saul-kun. Naruto-san is being taken care of by Sasuke, and Sakura has tied up Gaara. He's unconscious."
"Bring me to them."
Team Seven was in a much better state than in Canon when they faced Gaara. Despite Gaara being more murderous and losing control completely earlier this time around, Hinata's support was not to be underestimated. Naruto was only breathing hard from what seemed to be Chakra exhaustion, and Sasuke and Sakura had not been injured.
"Yo. Are you guys doing alright?"
"Saul-sensei..."
Sasuke nodded in greeting, while Sakura gave a small wave. Saul knelt down by Gaara. Inspecting him with the Mystical Palm Ninjutsu, he found that his chakra network had been completely overdrawn and wrecked by a massive amount of chakra. There was no way he'd even be able to use chakra in the short term, period.
There were also arrow wounds all over his body. None of them were life threatening however - the bleeding had already stopped. Wait, weren't Jinchuriki supposed to have highly enhanced regeneration? Maybe his earlier assessment about Gaara's chakra network was wrong...
Saul focused. His perception jumped to the Tenketsu, points where chakra could escape the body. He then commanded the skin to grow over Gaara's Tenketsu in his arms and hands, effectively 'sealing' his use of Ninjutsu until another medical professional came along and discovered what he did.
This is something he also did in Temari's case. He had put the woman underneath Hypnosis while he was gone, but her identity was particularly sensitive. Unlike the other test subjects in the Forest of Death, Temari was not allowed to go out and forage for food or water. The only thing she was commanded to do was to maintain her body as best she could by circulating her chakra while tied up and waiting.
In addition he had discovered she had made a summoning contract of some kind. The Seal was present on her body. He had sealed the Tenketsu that connected to the seal as a precautionary measure. Theoretically this should mean that even if someone had gotten into contact with whatever animal clan she summoned to try and reverse summon her back - the blocking of the Tenketsu there would prevent any exchange of chakra. Thus invalidating any attempt at locating her from the beginning. He certainly needed to do more research on the matter however.
"W-we weren't able to keep them all alive..." Naruto looked downcast. "The puppet guy was killed by Gaara before any of us could do anything about it."
Saul sighed. "That's alright..."
Sakura looked over at him as he stood up questioningly. "What about you? Did you catch Temari?"
Saul shook his head. "No, she preferred death to capture. There wasn't much I could do..."
"I see..."
"More importantly," Sasuke asked, glancing up at the two, "Did you guys hear that coming from the direction of the village? That wasn't a signal the village uses. That could really only mean two things. A signal for reinforcement-"
"Or a call to retreat." Saul finished.
Naruto got up, "If that's the case, then we need to head back!"
"Not so fast, Naruto. What do you think would happen if we ran into some Sunagakure ninja while going back to the village?"
"We'd beat the shit out of them, of course!"
Sasuke and Sakura however seemed to realize something from Saul's words and nodded.
Since Sakura didn't dare to touch Naruto anymore, Sasuke rose and patted him on the shoulder.
"Got it. We'll stay here and hide Gaara until everything blows over. I presume you made sure he no longer poses a threat when he wakes up, right?"
It was a pleasure working with people who had some common sense. Saul didn't have to work hard explaining literally everything.
"Exactly. Hinata and I will go to the village to request reinforcements for you guys."
Pakkun spoke up. "Actually, I'll let Kakashi know. You two don't have to worry about that."
He reverse summoned himself at that moment.
It was extremely odd for Saul, seeing a talking dog just interject itself casually into the conversation and speak. He had automatically excluded the thing from his mind after all.
"Well then. I've taken the chance to recover some chakra; I'll be needed at the village to heal any wounded. Stay safe."
The signal that sounded earlier was indeed a call for retreat. Saul and Hinata did not encounter any trouble on their way back.
Soon they found themselves walking openly in a field of tulips that lined the streets and grew out of cracks in various walls, leading directly to the Konoha hospital.
Shinno, the old man they had previously tied up, was now at work healing various Konoha ninja. He was using a mixture of the mystical palm and various tools / drugs to save on chakra. Yakumo and Anko had seemed to have relaxed their guard around him. Saul smiled. This old man's skills were for real, but you couldn't let your guard down around him because of this.
"Hey, I'm back."
"Saul-san!" Yakumo smiled.
"Hey." Anko greeted.
Saul sat up in one of the chairs in the reception, leaning back in the chair to relax.
"How was the old man? Did he behave?"
Yakumo answered in response. "Nothing suspicious from this guy, he genuinely healed many Konoha ninja."
Anko nodded along as she spoke in agreement.
"I see..." Saul opened one eye, glaring at the man. A bead of sweat slipped down his brow.
"I-I told you before... Yes? I am only a traveling doctor... You wouldn't think a harmless old man like me would be out to do something bad, right?"
He finished wrapping up the wounds of the Konoha ninja beneath him, having finished performing standard treatment. He had used up a lot of chakra now, putting up his little act in front of these guys. But he didn't have a choice.
Now that the ninja escorting him from the Land of Sky had been taken out, it was up to him to complete the mission. He needed to regain the method of cultivating the Zero Tails, after all.
These fools from Konoha most likely designated it as a medical technique of some kind and sent it to the hospital. That's the way it was presented after all. It was a harmless technique that merely siphoned away strong negative emotions and feelings like pain and suffering of its target, leading to less suffering. Not none. And it used a moderate amount of Chakra, not just a little, so its use was a luxury that only dedicated medical nin would learn.
Certain Genjutsu shared this effect to a much greater degree. If the correct portions of the mind were directly targeted by a Genjutsu, then one could completely eliminate pain, despair, sadness, etc. And they used less chakra as well. The Siphoning technique was just useless in comparison.
But it had a hidden effect. When used in combination with the 'Seed' of the Zero tails, a regenerating, persistent chakra would be formed when used on those with high levels of negative emotion. Its properties were extremely similar to tailed beast chakra, and when enough of it accumulated, it would amalgamate into a tentacle creature they called the Zero Tails.
He needed to gain these Konoha ninja's trust so that he could hopefully access their medical Jutsu archives. He was already so old after all... He had long retired from being a ninja, and his weak body could not fight. Shinno longed for the day where he could remake his body using the chakra of the Zero Tails...
Shinno forced a smile. "I'm running out of healing supplies. May I go have a look around for some more? I'll need them to conserve on chakra, after all."
"Sure!" Saul smiled, "I'll go with you. I happen to be quite familiar with the hospital after all."
Damn it!
"Thanks, oh ho ho..."
Author's Note: Here is more explanation on Shinno, for anyone interested. Like the Uzumaki's Village in the land of Whirlpools, Shinno was part of a 'village' called the land of sky that was ganged up upon by the Major Villages and completely destroyed. Yet he was always a spy for the village, working around various places as a traveling doctor. He met Tsunade and Orochimaru during this time.
In a period of time sometime before the start of Shippuden, Shinno learns that Konoha was actually the perpetrator who stole their technique to cultivate the Zero Tails. He infiltrates Konoha using his standard disguise and successfully finds and steals the technique to cultivate the Zero tails.
This is when he retreats from Konoha and begins his work to raise an apprentice of his, called Amaru. He cultivates their relationship over a long period of time, saving various people from their village. Then he gets the Land of Sky to destroy her village, leaving the woman extremely distraught. He is the only one left remaining who was precious to her, but he also fakes his own death right in front of her. This culmination of negative emotion is finally enough to awaken the Zero Tails.
I won't go over any more details here, but I saw the vulnerable Konoha during the Konoha crush as the best opportunity for a man like Shinno to infiltrate. He kept ties with Orochimaru as well, as shown in the movie, so he also would have been able to time things perfectly.