Isshiki Otsutsuki is one of the main antagonists in Boruto: Naruto Next Generations. He came to Earth a long time ago along with Kaguya Otsutsuki, however, was betrayed by her and thus spent most of his life looking for a perfect host to be revived into.
Using his tremendous power, he amassed quite a powerful bunch of shinobi and created the organization known as Kara. Isshiki's power goes beyond what any character in the Boruto series possesses. Hardly anyone can defeat him, but there are certain characters who can give him a good fight.
Updated on October 16th, 2020 by Josh Davison: Isshiki Otsutsuki was the devil on the horizon for some time who has finally arrived. He is an immensely powerful shinobi who controls a deadly organization in Kara. Ultimately, Isshiki had to take a host body in the form of Jigen, but this has not mitigated his power in the slightest. He is an Otsutsuki, a celestial being with access to the three main Dojutsu and virtually unlimited chakra. He has yet to face a shinobi who can truly defeat him, and he doesn't seem to be going away anytime soon. That said, there are a few more shinobi who can at least make Isshiki fight for his victory, and they clearly deserve a mention here.
15 Boruto Uzumaki
Boruto Uzumaki hasn't quite had the track record of his father. While Boruto is clever and determined, he isn't aiming to be Hokage and wasn't intent on becoming the most powerful shinobi. Despite that, Boruto has grown into a fairly powerful shinobi and has been trained in the Kama given to him by Kawaki.
That alone probably wouldn't be enough to stand a chance against Isshiki, but Boruto was able to access the powers of Momoshiki Otsutsuki after being possessed by the villain, including the Jougan. With these abilities, untrained as he is, Boruto might just stand a chance of making Isshiki break a sweat.
14 Killer Bee
Killer Bee is probably the second-most-powerful jinchuuriki after Naruto Uzumaki himself. He has long held a harmonious relationship with the Eight-Tailed Beast, and he has easy access to that deep well of power. He also has his powerful Lariot attack and is an incredible swordsman.
Killer Bee's powers haven't seemed to diminish in the time between Naruto and Boruto. He was attacked by Momoshiki and Kinshiki, but he was unable to conquer the duo. He was however, able to fool them with a substitution clone made by one of the Eight-Tails tentacles and escape.
13 Kakashi Hatake
Many think Kakashi Hatake well beyond his prime now that he has lost both Sharingan Eyes, but the Copy Ninja has proven himself still a formidable foe in Boruto. He has unleashed a new version of Lightning Blade through the Purple Lightning technique which may be even more powerful than the original. On top of that, Kakashi has acceess to the countless jutsu he copied over the years through his Sharingan, provided that he still has the chakra reserve for them.
Kakashi Hatake could not beat Isshiki, but that doesn't mean that Kakashi couldn't at least challenge the villain. Kakashi is clever, versatile, and still quite powerful. He could, at the very least, annoy Isshiki a good bit before being beaten down.
12 Kawaki
Kawaki isn't a shinobi in the traditional sense. He was intended to be the new vessel for Isshiki and was branded with the Kama. He was taught how to use that Kama by Isshiki himself, had his body modified, and was given Shinobi Ware to make him a formidable opponent.
Kawaki was strong enough to fend of Team Konohamaru and has only shown greater strength in the time since. He even helped Boruto to become a better warrior. Ultimately, Kawaki would likely give Isshiki quite a fight before going down.
11 Boro
A member of Kara, Boro is a monstrously powerful fighter. He made his proper introduction during the Naruto rescue mission and fought the new Team 7.
In terms of physical power and regeneration, few can match Boro. His strongest asset is his Dark Mist Jutsu that slowly paralyzes all those within its sphere. Boro can fight Isshiki Otsutsuki, but he's not going to defeat him no matter how hard he tries.
10 Toneri Otsutsuki
One of the strongest known Otsutsuki, Toneri is a descendant of Hamura Otsutsuki who also appeared as the main antagonist in The Last: Naruto the Movie. Being an Otsutsuki, it goes without saying that he is exceptionally powerful.
In his prime, he had access to the Tenseigan Chakra Mode and had enough power to completely destroy the earth. He was able to fight Naruto Uzumaki for quite some time but ended up losing from just one of his punches.
9 Delta
Another member of Kara, Delta is quite possibly the strongest female character in the Boruto world and she easily ranks among the strongest overall as well. Like Boro, her body has been enhanced with scientific technology that allows her to regenerate, extend her limbs to damage others, and even absorb all kinds of ninjutsu.
Furthermore, Delta can shoot a ray of light capable of completely destroying the target and negating their regeneration properties.
8 Kashin Koji
Kashin Koji is a clone of Jiraiya, one of the Legendary Sannin of the Leaf. He's an incredibly powerful shinobi who was skilled enough to take on Isshiki in a fight.
Koji is the only character to have severely damaged Jigen in a fight so far, and that says a lot about his capabilities. He also has access to Sage Mode and overall, he's simply a monster in battle.
7 Kinshiki Otsutsuki
Kinshiki Otsutsuki was Momoshiki's guardian and partner. He was quite a powerful character who matched Sasuke Uchiha when the two fought near Kaguya's castle in an unknown dimension.
Kinshiki's power is said to be great enough to split planets apart with ease. At his full power, he couldn't be stopped by any regular shinobi. Although strong, Kinshiki is far weaker than Isshiki.
6 Urashiki Otsutsuki
Urashiki Otsutsuki is an anime original character who appeared in Boruto: Naruto Next Generations. As an Otsutsuki, he was incredibly powerful and had access to several Kekkei Genkai. In theory, Urashiki could've been one of the strongest, if not the strongest, characters in the series.
However, his showing in combat made him seem very average. He was defeated by Boruto Uzumaki, kid Naruto, and Jiraiya's combined efforts.
5 Sasuke Uchiha
Sasuke Uchiha is the strongest shinobi alive in the world, along with Naruto Uzumaki. He's the last reincarnation of Indra Otsutsuki and he also possesses half of the Sage of Six Paths' powers.
Sasuke is a tremendous fighter who, according to Isshiki, is a bigger threat than Naruto Uzumaki, mostly because of his analytical skills. He's strong enough to give Isshiki a fight, however, he would end up losing the fight alone.
4 Naruto Uzumaki
Naruto Uzumaki is the Seventh Hokage of Konohagakure and, along with Sasuke, the strongest shinobi alive right now. He possesses tremendous power that allowed him to put up a fight against even Momoshiki Otsutsuki to an extent.
Although Naruto can do the same with Isshiki, he cannot defeat him in battle unless Sasuke Uchiha is by his side. When the two fought, Naruto proved to be vastly inferior to him even with his Six Paths Sage Mode active.
3 Momoshiki Otsutsuki
Momoshiki is one of the very few characters in the series who is actually capable of defeating Isshiki Otsutsuki. He appeared in the series along with Kinshiki to hunt down Naruto Uzumaki.
After absorbing Kinshiki, his powers were great enough for him to overpower Naruto and Sasuke individually. Although Momoshiki lost to them, his knowledge of the Otsutsuki clan and Isshiki could possibly allow him to defeat the man.
2 Hagoromo Otsutsuki
Hagoromo is the fabled Sage of the Six Paths who founded the shinobi way and conquered the Ten-Tailed Beast, sealing it within himself. He was one of the two sons of Kaguya Otsutsuki, the other being Hamura — the founder of the Hyuga Clan. Hagoromo is an unfathomably powerful warrior who, in all likelihood, would probably beat Isshiki on his own.
That said, Hagoromo died long ago, while Isshiki is still alive. Take that to mean what you will. It may be that Isshiki could still conquer Hagoromo. In any case, it wouldn't be an easy fight for either combatant, but it would be quite exciting to watch.
1 Kaguya Otsutsuki
Just like Momoshiki Otsutsuki, Kaguya is one of the few characters who are strong enough to fight and match Isshiki Otsutsuki in battle. Kaguya partnered Isshiki at one point and thus she knows everything about his abilities.
What's more, she also nearly killed him in battle, which implies that given the chance, she has the power to pull off such a feat. At full power, Kaguya Otsutsuki is definitely great enough to fight Isshiki Otsutsuki on par and possibly even defeat him.