In the world of Boruto, Mitsuki has proven to be one of the most intriguing characters in the young ninja's life. After finding out he's the 'son' or genetic clone of Orochimaru, fans expected the boy to have some ulterior motive and turn on Naruto's son and the entire Konoha someday, but since we've met him, Mitsuki has been nothing but loyal, kind and genuine.
As much as he's Boruto's ally, Mitsuki is already ahead of his peers because of one integral weapon he boasts: Sage Mode. As you may recall, it took Naruto months to learn this with Master Jiraiya and the Toads, but Mitsuki has already shown immense promise with it in the few sequences he's used it. With that in mind, let's look at how powerful Mitsuku's Sage Mode really is and what he can do with it.
HOW DID MITSUKI ACHIEVE SAGE MODE?
While Naruto and several ninjas before him had to train diligently and become one with nature so as to harness this energy, Mitsuki was simply engineered with special genetics allowing him to harness this strength. According to some fan speculation. Orochimaru implanted the cells, not just of himself, but of the First Hokage of Konoha, Hashirama, into the boy, which basically makes him a walking vessel for Sage Energy. Hashirama was a master of Sage Transformation, ergo why it appears Mitsuki's like this, not to mention Orochimaru may have added a Cursed Seal to enhance him.
Mitsuki refined the technique repeatedly with Orochimaru throughout several intense and high-pressure trials, and in one such incident, the full manifestation was actually activated by an emotional trigger. When Orochimaru and another older Mitsuki clone, Log, tried to force the boy to choose his fate, he decided to break ranks and make his own way. This led to his Sage Mode and overall transformation kicking into high gear, and it proved to his creator the boy was even more special than he thought.
WHAT CAN MITSUKI'S SAGE MODE DO?
Mitsuki already has the ability to stretch his limbs like Marvel's Mister Fantastic and use snakes himself, which get amplified when he's in Sage Mode. When he triggers it, he develops a green aura around him that signifies a very strong chakra flow, and this energy ironically proceeds to take the form of protective snakes. These snakes act as extra limbs and are a far cry from the likes of Orochimaru and Kabuto in the past who could only project their powers using real snakes, which made them more vulnerable.
Mitsuki's abilities seem tied more to the Great White Snake, the Snake God, in the Ryuchi Cave, evidenced by the horn that grows from his forehead like a big viper or dragon when he's in this mode. Most notably, he has lightning-fast speed that seems to rival the fastest shinobi ever, the Yellow Flash, who's also Naturo's dad Minato. Another key characteristic for the boy is this mode acts as a bubble that preserves Mitsuki's life, as seen where he fought Shino underwater in an advanced training session in Konoha, proving he really is connected to the elements.
HOW STRONG IS MITSUKI'S SAGE MODE?
He's only used it a few times in battle because he fears if it goes public, Konoha will see him as a deviant as someone so young shouldn't have access to such a power outlet. That said, Mitsuki did confront and beat Shino with it. Seeing as Shino's a famous bug-master and one of Konoha's best instructors, that says a lot. He also managed to outwit Orochimaru and Log, and grab some mystical scrolls from them in their climactic trial, while also illustrating he has the mental power to show restraint amid this prowess.
In another incident, Mitsuki used these powers to ward off a rogue faction of ninjas led by Kū, making it obvious that he makes up for what he lacks in experience with raw, natural ability and the unique skill of learning on the fly. At this remarkably young age, Mitsuki's nowhere near what we saw from Naruto's Sage Mode in his Shippuden days against Pain and company, but he's still a solid powerhouse. It's clear that with time and his ever-evolving DNA, Mitsuki's trajectory will take him to heights his creator could only ever dream of.