Momoshiki Ōtsutsuki

was a descendant of the Ōtsutsuki clan and the main antagonist in Boruto: Naruto the Movie.

Personality
Momoshiki, while normally calm and collected, had sadistic tendencies, which was shown during his and Kinshiki's attack to Konoha, where he laughed after seeing distressed citizens while firing his elemental attacks.

Momoshiki also thought very lowly other people than himself, calling Naruto, Sasuke, Boruto and Sarada "lowly beings". He even absorbed Kinshiki without second thought.

Appearance
Momoshiki had pale skin, white hair with a pale-blue tint which he kept in a long ponytail. His hair was parted down the middle in a zig-zag pattern, and his head was adorned with a pair of flat, curved horns which more resembled the ears of an animal. He had delicate facial features and his eyebrows were cut very short as a symbol of nobility. He dressed in a traditional white kariginu hunting robe, baggy pants, a pair of tengu-geta, and a single black glove on his left hand, with a hole cut into the palm to display the Rinnegan which was red colour. He also wore a transparent veil over his head.

After absorbing Kinshiki Ōtsutsuki, Momoshiki's appearance took a drastic change including; dark-brown skin, his horns changing into more typical sharpened bull horns, white markings under his eyes and a massive increase in size. His Rinnegan on his palms turned purple and awakened a third one on his forehead.

Abilities
Momoshiki was an extraordinarily powerful being who, alongside Kinshiki, was deemed as a threat greater than Kaguya Ōtsutsuki, the progenitor of chakra. After absorbing Kinshiki, he became able to fight on equal ground with Sasuke Uchiha and the Seventh Hokage Naruto Uzumaki, who were both powered by the Rinnegan and Six Paths Sage Mode respectively.

Chakra and Physical Prowess
As an Ōtsutsuki, Momoshiki is gifted with extremely powerful chakra. He can also absorb any technique that he encounters, as well as an opponent's chakra. He also has shown proficiency in taijutsu, as well as enormous strength, sending Naruto back crashing through a wall with a single kick. He can also move swiftly to avoid enemy attacks.

Upon absorbing Kinshiki's power, Momoshiki became strong enough to battle both Naruto and Sasuke at the same time despite Naruto being in Six Paths Sage Mode. However, ultimately he was outfought in that area and had to turn to his ninjutsu to gain the upper hand on Sasuke.

Byakugan
Momoshiki wielded the Byakugan in both eyes, granting him near 360° vision (with the presumed exception of a small blind spot at the upper thoracic vertebrae), x-ray vision and the ability to see the chakra pathway system amongst other abilities.

Rinnegan
Momoshiki wielded the Rinnegan in the palms of his hands. He could absorb ninjutsu with his right, and utilise said ninjutsu with his left. By using his Rinnegan power, he can also turn any target into chakra edibles, grant him their abilities once consumed. Unlike Hagoromo's and Sasuke's, Momoshiki's Rinnegan wasn't light purple, but red, resembling the Rinne Sharingan. However, after transforming from his absorption of Kinshiki, the Rinnegan in Momoshiki's palms turned purple and he gained an additional purple Rinnegan on his forehead. Like other users of the Rinnegan, he could create Black Receivers as well.

Ninjutsu
With his Rinnegan, Momoshiki mastered all five elemental nature transformations easily through absorbing his enemies' chakra. After absorbing an opponent's technique, he could enhance it with his own chakra to use it on a much greater scale, as seen with Gyūki's Tailed Beast Ball and Shikamaru's Shadow Sewing Technique. Momoshiki's Fire Release is particularly strong, able to overpower Sasuke's Susanoo and give him a bad burn despite the technique being enhanced by Six Paths Chakra. Momoshiki could also create living things by manipulating natural aspects from his surroundings: from wooden snakes made from the Shinju's roots, a demonic fire phoenix, to a giant lava golem which was powerful enough to battle a Susanoo-clad Kurama. Momoshiki was also capable of flight.

Bukijutsu
In battle, Momoshiki wielded a black staff, which he used it proficiently to hold his own against a kenjutsu user. After absorbing Kinshiki, he became capable of creating various red glowing ninja tools such as a sledgehammer, swords, halberd, kris, celurit, and chains and appears very skilled in the use of all of them.

Boruto: Naruto the Movie
Momoshiki and Kinshiki encountered Sasuke in another dimension as he was seeking information on a threat greater than Kaguya Ōtsutsuki. In a blizzard, Kinshiki fought against Sasuke, who was nearly overpowered by Kinshiki's monstrous strength and barely escaped with his life. Following Sasuke from afar, Momoshiki and Kinshiki desired to capture the Nine Tails by kidnapping its current jinchūriki: Naruto Uzumaki.

Momoshiki and Kinshiki appeared in Konohagakure during the Chūnin Exams and created a massive chaos. Momoshiki remained on the side while Kinshiki destroyed most of the arena and tried to attack Sasuke and his daughter. Momoshiki calmly walked past a frightened Boruto, who tried to use his Kote to attack him but all of his attacks were absorbed through Momoshiki's Rinnegan. Sasuke related to Naruto his past encounter with the two enemies and they are a stronger threat than Kaguya. When asked by Naruto what they wanted, Momoshiki explains he and Kinshiki want to gather Kaguya's scattered chakra and cultivate it into cinnabar panacea, which he says will grant them eternal youth and supernatural powers. Because of Kurama's powerful chakra, they desired to take Naruto and extract the beast so they could use it for their own purposes. Momoshiki and Kinshiki attacked Naruto, Sasuke, and their children, leading Naruto and Sasuke to combine Kurama and Susanoo to shield themselves. All the while, Momoshiki laughed hysterically at their efforts. To end the battle, Momoshiki created a giant black ball that was amplified by the technique he stole from Boruto and launched it upon them. Ultimately, Naruto allowed himself to be captured by Momoshiki and Kinshiki to protect his son, Sasuke, and Sarada.

Momoshiki and Kinshiki took Naruto to another dimension and bound him to begin the ritual of extracting Kurama from inside him. Sasuke, Boruto, and the four other Kage arrived to rescue Naruto. Momoshiki fought Sasuke while the other Kage fought against Kinshiki and got defeated with ease. Wanting to finish everyone off once and for all, Momoshiki turned Kinshiki into a chakra pill and swallowed him, which increased his strength and his body underwent a drastic change. Naruto and Sasuke fought against him and almost had the advantage until Momoshiki briefly knocked Naruto out and severally burns Sasuke with his Lava Release. However, they managed to defeat Momoshiki by combining Naruto's Tailed Beast Mode with Sasuke's Susanoo. However, Katasuke used his Kote in an attempt to kill him for good, but his attacks were absorbed by Momoshiki, restoring his strength. He captured the other Kage with his technique and tried once more to extract Kurama from inside Naruto. With no other options, Sasuke decided to have Boruto use Rasengan to put an end to the threat. Boruto hit Momoshiki with his small Rasengan and freed his father and the other Kage. Naruto then led Boruto his chakra to help his son create a Parent and Child Rasengan while Sasuke distracted Momoshiki long enough for Boruto to launch his attack on Momoshiki, destroying him for good.

Trivia

 * Similar to how Kaguya was named, Momoshiki's naming convention seems to follow the Japanese folklore motif. It is a reference to Momotarō, while Kinshiki is a reference to Kintarō.