Momoshiki Ōtsutsuki

was a member of the Ōtsutsuki clan.

Background
Momoshiki and his father Kinshiki, originate from an unknown dimension, which has a God Tree, whose power supply has been depleted. Like Kaguya Ōtsutsuki, they also wanted to recollect all chakra into a new Chakra fruit, only to create medicine that could sustain their godlike power, youth, and longevity. Fearful of their arrival, Kaguya created the White Zetsu Army in order to fend off against them should they ever attempt to steal her chakra.

Personality
Momoshiki was typically calm, collected, and calculating. However, he had been prone to demonstrate sadistic tendencies, which was shown during his and Kinshiki's attack on Konoha, where he laughed after seeing distressed citizens while firing his elemental attacks. Momoshiki also had a severe superiority complex and thought very lowly of people other than himself, calling Naruto, Sasuke, Boruto, and Sarada "lowly beings". Likewise, he also cared very little for other people, even his own father. When he was in a difficult situation, he absorbed Kinshiki without a second thought in order to claim more power for himself.

Similar to Boruto Uzumaki at the beginning of the film, Momoshiki was also uninterested in hard-work, preferring to absorb and use the techniques of others instead of relying on his own personal strength. Any effort disgusted Momoshiki, and he was even greatly angered when his clothes were ripped during his final battle against his enemies. He is also very wasteful with his powers, never implementing any attempts with strategy to conserve his Chakra, and always taking it for granted that he will simply be able to replenish his Chakra with what he gains from 'cinnabar panacea' (Chakra Fruit and Chakra pills), and Chakra from any attacks he absorbs, and that his powers alone secure him victories. As is fitting of his lazy personality, he was easily intimidated when opponents powerful enough to pose a threat to him learn his weakness and rely on taijutsu to fight him. Sasuke and Naruto both agreed Momoshiki's personality is a mirror image of Sasuke's when he was bent on killing Itachi. However, upon seeing Momoshiki coldheartedly consume his own father and brutalize his fellow Kage, Naruto remarked that Momoshiki wasn't a man at all, or Sasuke's mirror image, but a simple monster who needed to be put down.

Although believing himself to be superior to everybody, Momoshiki is not completely unable to accept defeat, as after death, his spirit lingered enough to leave Boruto a foreshadow of his future, showing no outward anger nor hatred otherwise. In the anime, his mischievous nature also disregards the laws of his clan.

Appearance
Momoshiki had pale skin, and pale-blue hair 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 resembled bulls horns (unlike Kaguya's, who's had resembled rabbit ears). 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 for his Rinnegan, which was red in colour (purple in some depictions). He also wore a transparent veil over his head.

After absorbing Kinshiki, Momoshiki's appearance took a drastic change including; black sclerae, white irides, dark-red skin, a pointy chin, fangs, claws on his hands and feet which were exposed, white hair, ponytail enlarged and became much spikier, larger, sharpened bull horns, white markings under his eyes and a massive increase in size. His Rinnegan on his palms turned purple and he awakened a third one on his forehead. In the manga, Momoshiki's appearance is radically different upon absorbing Kinshiki. His body becomes lithe and covered with a black mark, his horns are far longer and curve back, and all his dōjutsu turn golden.

Abilities
Momoshiki was an extraordinarily powerful being who, alongside Kinshiki, was deemed a threat greater than Kaguya. He was capable of holding his own against multiple Kage-level opponents simultaneously, as well as defeating a perfect jinchūriki. After absorbing Kinshiki, he was able to defeat four Kage at the same time with extreme ease and he could fight near evenly with Sasuke Uchiha and Naruto Uzumaki, who both utilised the Six Paths Chakra. Being an Ōtsutsuki, he possessed extremely powerful chakra and had the ability to fly. At the cost of a large amount of chakra from eating multiple pills, Momoshiki could use space–time ninjutsu to transport Kinshiki and himself between dimensions. Not unlike Hagoromo, Momoshiki's spirit is remarkably powerful, able to continue interacting with the living world even after dying for a period of time. To which, he was able to bestow Boruto with special mark of unknown nature before disappearing.

Byakugan
Momoshiki wielded the Byakugan in both eyes, granting him a near 360° field of x-ray vision (with the presumed exception of a small blind spot at the upper thoracic vertebrae), and the ability to see the chakra pathway system. Using it, he could see Kurama's chakra that was sealed within Naruto. In the manga, Momoshiki could use his Byakugan to read the fate of other people, though it didn't allow him to see his own fate.

Rinnegan
Momoshiki wielded a pair of Rinnegan in the palms of his hands, which he could use to absorb ninjutsu with his right, and utilise said techniques with his left. Also with his right Rinnegan, he could turn a target into pills, which when eaten, grants him youth and their chakra, increases his muscular tissue, and can transform his entire body in the case of consuming Kinshiki's chakra. Unlike other Rinnegan wielders, Momoshiki's Rinnegan was initially red in colour instead of light purple. 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. He could create black receivers as well, which he used to either fight with, or fire at an individual to impale and restrain them.

Ninjutsu
Momoshiki could absorb an enemy's technique and utilise it on a much greater scale, as seen with the Tailed Beast Ball, Shadow Imitation Technique, and the Rasengan, which he proclaimed to be capable of making a limitless number of. He could also create glowing red weapons, which he used in the manga to sever his planet's God Tree. He had some knowledge in fūinjutsu, evident from his attempts to extract Kurama from Naruto's body.

Nature Transformation
With his Rinnegan, Momoshiki could use all five elemental nature transformations easily through absorbing his enemies' elemental techniques. He could create enormous elemental creatures, such as a fire pheasant, and a golem, which was powerful enough to battle a Susanoo-clad Kurama. Momoshiki's Fire Release was strong enough to overpower Sasuke's Susanoo and severely burn him. He could also perform Wood Release, capable of manipulating the God Tree to create wooden spikes and dragons. In the novel, Momoshiki could also use the Ice Release and showed prowess in creating an absolute zero blizzard, as well as a downpour of meteorites, after absorbing the ninjutsu that were generated through Katasuke's Kote.

Academy Arc
While eating, Momoshiki was approached by Kinshiki after investigating Kaguya's dimension. He noted tears in it and that its space curvature was over 16, which was very abnormal and must be reported to their clan. Wondering what Kaguya did do, Momoshiki told him to prepare to depart instead.

Versus Momoshiki Arc
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, while Momoshiki watched from afar and was enticed by the power of Sasuke's Rinnegan. After Sasuke escapes, Momoshiki and Kinshiki eventually made their way to the real world and began their quest to gather chakra. They first encountered Killer B, and Momoshiki easily manages to defeat him by absorbing his attack and using it against him. He then absorbs Gyūki's chakra from within Killer B and leaves him unconscious, despite the attack, Killer B survives. Unsatisfied with their chakra consumption, they then focused their attention on their next objective: capturing the Nine-Tails by kidnapping its current jinchūriki, Naruto Uzumaki, the Seventh Hokage.

Momoshiki and Kinshiki appeared in Konohagakure during the Chūnin Exams and created massive chaos. Momoshiki kicked Naruto out of the arena and 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 their purpose based on what was deciphered from Kaguya's scroll 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 into a new Chakra fruit and complete what Kaguya failed to do by cultivating it into a new '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's chakra 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 powers he stole from Boruto and launched it upon them. Ultimately, Naruto allowed himself to be captured by Momoshiki and Kinshiki while Sasuke protected Boruto and Sarada.

Momoshiki and Kinshiki took Naruto to another dimension and bound him to begin the ritual of extracting Kurama's chakra 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 was 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 imprisons Naruto in boulders and severally burns Sasuke. However, Momoshiki was severely weakened from the combined efforts of the pair.

When Katasuke used his Kote in an attempt to kill him for good, his attacks were absorbed by Momoshiki, restoring his strength. He captured the other Kage with the Shadow Paralysis Technique and was about to kill the other Kage, except for 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. Enraged at Boruto for damaging his garments, Momoshiki absorbed more chakra pills and increased his strength. Naruto then lent 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. First, Boruto ambushed Momoshiki with a shadow clone to take out his Rinnegan and then attacked him with his Rasengan, which collided with Momoshiki's own Rasengan look-alike, destroying him for good.

Momoshiki's spirit stayed intact for a while, noticing that Boruto could feel his presence thanks to his blood of the Byakugan users. He approached Boruto and told him that despite his inability to foresee his own fate, he could see Boruto's fate clearly. Momoshiki warned him that someday his blue eyes would take everything from him and that he's no longer an ordinary human after defeating a god. He also left a mark on Boruto's right palm and added that he should continue to follow his own path before disappearing.

Influence
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.

Trivia

 * Momoshiki's ability to create a dog, monkey and pheasant is influenced by the the tale of Momotarō, who befriends the three animals.
 * Shortly before and after absorbing Kinshiki, Momoshiki's Byakugan are depicted without veins in the manga.