WARNING: The following contains spoilers for Boruto: Naruto Next Generations Episode 175, "Beyond The Limits!" now streaming on Crunchyroll.
The Boruto anime hasn't been kind to Mitsuki since he went into Sage Mode to fight Deepa. The toll it took resulted in him returning home to Konoha with a badly broken body. This was made even worse when his parent, the insensitive Orochimaru, treated him like a mere object -- a weapon that could be scrapped for another clone.
It even worried the older clone, Log, as he felt Mitsuki might be discarded and replaced without Team 7 ever knowing. Thankfully, that hasn't happened as the young snake ninja returns to action in Episode 175 to help Boruto and Sarada, all thanks to a shocking sacrifice.
As Victor battles Konohamaru and Orochimaru, Boruto and Sarada seek revenge against Deepa. However, the Kara terrorist is even more powerful than expected, and despite Boruto's new Rasengan and Sarada's Sharingan, he gets the better of them. However, just as Deepa's about to enact some killing blows, the hooded figure we saw last week with Orochimaru arrives to protect the ninja... unmasking to reveal Mitsuki!
This reveal is a bit confusing because the last time we saw him, he had just gotten out of a coma but his organs weren't regenerating. Now, he seems to be up to scratch, using his snake transformations and lightning techniques to bolster Team 7 once more. Although, as quick as he is and as hard as he hits, Mitsuki also suffers another beatdown from the cannibalistic Deepa, who decides that this time he'll feed on the teens as he thinks they'll finally make a sumptuous meal.
Luckily, the shinobi trio adapts and creates a strategy that breaks Deepa down, coinciding with Victor's defeat and the end of the God Tree clone. Konohamaru, however, wants to know how Mitsuki entered the battle as he was left near-dead the last time he saw the ninja. Orochimaru has a sly disposition about him, confessing someone sacrificed their body to revive the kid, and the show cuts to Log recovering with an I.V. hooked up to him. It seems he offered his insides up as a transplant -- to which extent we really don't know.
It's a very noble move as Log, reinforcing him shifting away from being Orochimaru's sinister servant and more towards being Mitsuki's caring brother. We're eager to know, though, if he'll recover because Log hasn't played a big role in the manga. Fans think this selfless act could result in him dying, which would explain his limited role in the books, but other theorists believe this also presents Orochimaru another chance to experiment with Log and upgrade.
It does seem as though the real Mitsuki's back and is not simply another clone, so between Orochimaru monitoring his progress and possibly trying to perfect Log's body, and maybe then Mitsuki's, it's going to be a busy time in the Sannin's lab.