Plane Walking

 is a secret-Space-Time Ninjutsu created by Ryūken Senju who later on passed on this ability to Takumi Uchiha and Hotaru Yanma. It was also considered his signature technique.

Overview
It apparently the only real space-time ninjutsu at Ryūken's disposal. It allowed him to travel between different dimensions and universes and cross over different planes of existence or travel across various forms of reality. User can travel to other planes of existence, myriads of different realities all simultaneously coexisting within the same expanded cosmology. Planes are often multi-layered and likely endless in number, though they are usually organized into local cosmologies centered on a prime nexus plane. Planes and their inhabitants exist in an infinite diversity of forms and natures, and users are bound to meet untold wonders and dangers during their travels, as well as exotic artifacts, arcane knowledge and unique power sources. He can travel to other possible worlds that can or could've happened from the endless abyss of alternate outcomes and continuities, being able to taste how dissimilar those probable worlds are to his own. Consequently, one might take interest in one or a couple worlds and may create a permanent stay.

Though while it be restricted to the context of the story, possible futures, pasts, and even present events withhold endless amounts of variety in spite of how distant or close it is to the original line of events, and users will inevitably find horrors, pleasures, joy, and sadness that could have been and still can unfold. User can distort the otherwise intangible and invisible barrier that separates dimensions. This allows them to forcefully shift their own existence to another dimension, traveling through dimensions and causing tears within the walls that separate them. Which explains, how Ryūken did it.

He can also use this technique offensively.