"Ah. They do exist."

"And there's - different versions of the same people, across them. Different magics, different worlds, different histories... The - mind in this body - isn't originally from this one. My home world is run by an omnipotent, easily bored asshole, who I think swapped my mind and this world's Sasuke's just after the Uchiha Massacre, probably to see what would happen."

"The technique you saw was a fairly basic part of one of the two magic systems native to that world, arcane magic. I was at the peak of possible power in that. I am actually qualified to teach arcana - I was a professor for a few decades - but most people don't get any talent until their mid or late teens at the earliest, and it can take years to learn even the basics. It's apparently possible to cheat with the sharingan, though, since arcana is based in part around memorization, so I've been able to teach Kakashi a few things."

"What are your intentions here, what do you suppose is the original Sasuke's fate, and how likely is - interdimensional contact?"

"I mostly intend to survive long enough to invent interdimensional travel, and while I'm here protect the people I've come to directly care about - mostly Naruto, Chihiro, and Kakashi - or that I have a responsibility for - like Elieyha, and anyone placed under my command. I'd like to get this world up to my home world's minimum standards for not a shitty place to live, which I'm hoping to do through spreading the more utilitarian pieces of arcana, through supporting reformers like Naruto, and through careful maneuvering with interdimensional contact."

"My home world almost never has permanent death. We have effectively infinite new planets to expand onto. The largest polity in existence has a robust universal basic income. There's some screwy politics some places, and interpersonal crimes still exist, but it's less severe. There hasn't been a war in a thousand years that involved people under age twenty one."

"For the original Sasuke - he would've been seven when dropped over, so probably my wife adopted him and got him therapy. I expect he's still in school, now, assuming time's passing evenly on both sides."

"If interdimensional contact from their end hasn't happened yet, it probably won't, at least not until a suitably narratively dramatic moment. I did mention a bored omnipotent asshole was involved, right? I'm fairly sure I can invent an interdimensional teleport, eventually, on my end, though that might take a decade or two. It might also take three or four years. Technique development's weird like that."

She considers him for a few long moments.

"Very well."

"Your orders are to develop a screening test for who has arcane talent, and who will best learn arcana quickly. You will continue on missions with your present team, for the most part, but I also want you on research and development. Of things useful to the Leaf, not just you. You will be provided with a suitable budget, and with political support, so long as your interests appear aligned with this village's. During the course of your research and development assignments, I want you familiarizing yourself with the hospital and with emergency medical procedures. If another major incident occurs, your assignment is to report immediately to the central medical coordinator. I won't pull you off missions for a hospital assignment - I know damn well the value of a field medic - but I expect you to handle major cases that fall more centrally under your magic's powers."

"And I want a full evaluation of your home world's major polities and their broad military capabilities and typical diplomatic goals."

He nods. "The screening test and evaluation might take time, but I'll get those to you as quickly as I can manage."

"You have a week."

"...Alright."

"Was there anything else?"

"No. You're dismissed, brat."

He nods, and goes to find Kakashi and let him know the talk went well, then to pour himself into recreating screening tests and national summaries...

This is going to be a long week.

A week later, after Sugira turns in his reports, the new chuunin of Team Seven are summoned for a mission.

A mission, together. It will be be good to get out of town for a while.

Definitely. (Sugira is possibly approaching burnout and wouldn't mind stretching his legs.)

Mission!!!

With his team!

(Who's their fourth member? What's the mission, actually...)

Rounding out the squad is Hyuuga Neji.

They're being sent to investigate some strange happenings near the ruins of Hidden Whirlpool. Missing travelers, lost ships, that sort of thing. It might be bandits, but the pattern doesn't exactly fit. Sasuke is designated team leader, and there's another, hidden part of the briefing for him to read privately.

He does so, once he's alone.

Tsunade suspects that Danzo has been using Uzusio as a clandestine meeting point with groups outside the village. While they're in the area, he's to look for signs of this and identify who he's been conspiring with, and if possible, for what purpose.

Great.

He makes a mental note of this, memorizes the briefing with his sharingan, then follows whatever procedures for getting rid of clandestine orders.

And then to get his team ready.

He'd like to know their impressions - he realizes they don't have much to go on, from the briefing, but it's better to be on the same page with what they think is potentially going on.

The Village Hidden in the Whirlpools has been abandoned for more than forty years. It is a common superstition in the area that it is haunted by the ghosts of the shinobi who died with it. It is unlikely that common bandits are the cause of the problems, as they would choose to base their operations somewhere else.

He nods - there's unlikely to be a lot of lucrative trade passing through, especially with the island's reputation and location. Local fishermen, smugglers, travelers trying to take a short-cut, treasure hunters... Not the wealthy merchants that pirates would be drawn to, though.

Therefore, the culprits will have reason to want their activities unobserved.

Neji would like to know if Naruto knows anything about the area.

Not at all. 

Do the patterns of where people and ships probably went missing seem to have a common path or area of vanishing? Like, if there were some really aggressive smugglers or similar who were enforcing no one seeing them... It'd at least give them a place to start...

The danger zone is fairly broad. Which is perhaps evidence that whoever is doing it is aware enough to realize that too tight a defense is as good as a signal flare.

Or they've got a broad base of operations, or they're highly mobile and disrupting anyone who crosses their path...

Also possibilities. Reason to approach with caution, in any case.