Momoshiki Ōtsutsuki

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

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
Using unknown methods, Momoshiki was capable of floating. He could not only absorb chakra, but a person's physical body, turning them into chakra-filled edibles, which, when eaten, would transform Momoshiki and grant him their abilities. After obtaining Kinshiki's chakra, Momoshiki was granted his ability to form various glowing red weapons. After absorbing nature transformations, Momoshiki obtained the ability to use them simultaneously, but it's unknown whether the power is permanent or not. These unique abilities enabled him to fight equally with the likes of Sasuke Uchiha and the Seventh Hokage Naruto Uzumaki, who were both powered by Six Paths Chakra with the Rinnegan and Six Paths Sage Mode respectfully.

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 a degree of mastery in taijutsu. He can also move swiftly to avoid enemy attacks.

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 his palms. With the one in his right hand, he could absorb all kinds of ninjutsu. With the one in is left hand, he could release the ninjutsu he absorbed and fire it. He was even capable to absorb Shikamaru's Shadow Sewing Technique, and later used it, even at global scale to pinned down anything in his planet. Unlike Hagoromo's and Sasuke's, Momoshiki's Rinnegan wasn't light purple, but red, resembling the Rinne Sharingan. However, after transforming due to absorbing 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 the power of his Rinnegan, he mastered all five elemental nature transformations easily through absorbing his enemies chakra. By using his Rinnegan power, he also capable to turn any target into chakra edibles, where if its consumed, grant him his target abilities. Also unique to him was his ability to use the Tailed Beast Ball after initially absorbing Gyūki's, which he made many times more powerful with his own chakra.

Another testament of his power, he was able to create living things by manipulating natural aspects from his surroundings: from wooden snakes from the Shinju's roots, demonic fire phoenix, to a giant lava golem which was powerful enough to fight on par with a Six Paths Sage Mode-enhanced Susanoo-clad Kurama.

Bukijutsu
In battle, he wielded a black staff, which he used it proficiently to hold his own against a kenjutsu user. After absorbing Kinshiki, he capable to create 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. In a blizzard, Kinshiki fought against Sasuke, who was nearly overpowered by Kinshiki's monstrous strength and barely escaped with his life. As kinsmen to Kaguya, 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 about his past encounter with the two enemies and they are the threat he has been searching for. Momoshiki and Kinshiki attacked Naruto, Sasuke, and their children, leading Naruto and Sasuke to combine their Tailed Beast Mode and Susanoo to shield themselves. All the while, Momoshiki laughed hysterically at their efforts. Ultimately, Naruto allowed himself to be captured in Momoshiki and Kinshiki's techniques 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.