Karasuki

is a turtle-like artefact belonging to the Ōtsutsuki clan.

Personality
Karasuki talks in a very matter-of-fact nature. It does not respond beyond explaining the situation or asking for instructions. Despite belonging to the Ōtsutsuki clan and even referring to its members in a respectful manner, it notes that it has no true loyalty to one side. It only exists to perform temporal travel and instruct people about the rules of performing such.

Abilities
Karasuki apparently has a very long lifespan, having existed for centuries. It has the power to transfer people through time. However, it requires a lot of chakra to perform.

Time Slip Arc
Karasuki was eventually discovered by Konohagakure and taken there for research. Realising what Konoha really had, Urashiki Ōtsutsuki saw this as an opportunity to more easily get the Nine-Tails' chakra. Once sneaking into the village, Urashiki removed the seal on Karasuki to awaken it. Urashiki instructed the turtle on his goal and gave it enough chakra to perform his trip. Before leaving, they were intercepted by Boruto Uzumaki and Sasuke Uchiha. They entered a void where they battled, knocking Urashiki off a ledge "too soon" for him. Upon arriving at the new destination, shortly after the younger Sasuke's defection from Konohagakure, Karasuki explained the situation. It also revealed that Urashiki would not be arriving for another few days due to Sasuke's interference and the two Konoha-nin must avoid as much interaction with the past as possible or risk severe changes to the future as they know it. The turtle was then stored away in Boruto's pouch.

Days later, after Urashiki was finally defeated and killed, Karasuki was used to return Sasuke and Boruto to their proper time. Noting that it had extra chakra to go somewhere else after absorbing some of Kurama's leaking chakra, Sasuke and Boruto convinced Karasuki to use that chakra to go on a journey of self-discovery and find what it wants to do with its life.

Trivia

 * Karasuki, like Urashiki, is inspired by the tale of Urashima Tarō, in which the fisherman Urashima rescues a turtle which carries him to the Palace of the Dragon King as thanks. There time passes differently, and when he emerged after only a few days of feasting and entertainment, he found that a hundred years had passed for the outside world.