Naruto's new technique was just revealed, but we overlooked it.

[Sync]

Reason why RS is needed in hermit mode is because its a double edge move. Because if Naruto just keep using RS all the time his hand will cannot heal/draw chakra sever damage of the cellular. But with Sage / Kyuubi Naruto body is now able to heal faster than ever. So I say he trying to continue his training but the picture on the side where it shows black it probably show that it can be a FLASHBACK but the thing you guys think as a smoke it can be a cloud at night. WHY? who knows this is a narutouniverse anything can happen.

 

[QwertyHero]

I don't think so. And I don't this its RS either. The way I took the picture everything was on fire. RS has some wind chakra in it. How does wind catch trees on fire?

No, the trees aren't on fire, the trees just look different in Toad Mountain.
And even if the trees were on fire, you could argue that Naruto's applying the fire element into the RS, thus making it more powerful and fire-y I guess.
And another thing, the smoke may just be like debris and dirt in the air caused by the RS.
Seeing smoke doesn't necessarily mean there's fire.