Urashiki Otsutsuki has been a curious addition to Boruto: Naruto Next Generations ever since the villain was first introduced. A member of the Otsutsuki Clan completely original to the anime, Urashiki disappeared for long stretches of episodes until returning for the time travel arc celebrating Naruto's 20th Anniversary. He continued to showcase new and interesting powers as the fight with Boruto and Naruto went on, but the last episode of the series had him cornered and defeated thanks to their quick teamwork. But it wasn't the end as Urashiki unveiled a terrifying new form during Episode 135.
Episode 135 of the series sees Urashiki cornered and thus decides to devour his Rinnegan eyes. This then grants him a whole new level of power in which he transforms into a being with Yellow Rinnegan much like Momoshiki Otsutsuki did during the final battle of the Chunin Exams arc.
Like the other advanced Otsutsuki Clan forms showcased in the series thus far, this new transformation gives Urashiki a huge boost in strength. No longer needing to use his fishing rod to steal the chakra of others, this transformation turned Urashiki into a bird like creature that speeds around the skies with ease. This gave Naruto, Boruto, and Jiraiya lots of problems as Urashiki wasn't easy to deal with in this form.
But even with this transformation, Urashiki is still the same character as his ego and hubris meant that he left quite a few openings. This proved that while Urashiki was powerful, he was not indestructible. It took Boruto and Naruto finally utilizing their joint jutsu to do any critical damage to Urashiki in the end. But this transformation was definitely fearsome.
Originally created by Masashi Kishimoto for Shueisha's Weekly Shonen Jump in 1999, Naruto follows a young ninja, with a sealed demon within him, that wishes to become the leader of his home village. The series ran for 700 chapters overall, and was adapted into an anime series by Studio Pierrot and Aniplex that ran from 2002 to 2017. The series was popular enough to warrant a sequel, Boruto: Naruto Next Generations which is set several years after the events of the original Naruto story and features the children of many of its key characters such as Naruto and Hinata.