A fiery energy-like power with a dark side origin was employed by Darth Sidious when he attacked both Ezra Bridger and Ahsoka Tano. It first appeared as brilliant blue flames, functioning as both a weapon and an instrument to restrain and pull individuals closer, as demonstrated with Ezra. Its appearance resembled a solid rope. This concrete form created a link between them, granting Sidious brief entry into the World Between Worlds. This energy was created using a Sith ritual altar, but the user was able to move away from the altar and conjure the energy directly from their hands.
Tano demonstrated that someone strong in the Force could also defend against this energy during her battle with Sidious. However, this defense was incredibly draining for her, leaving her depleted. Furthermore, any physical forms of this energy could be severed using a lightsaber; Ahsoka, for example, utilized her lightsabers to slice the energy that was binding Ezra's leg, thereby breaking the connection and causing Sidious considerable pain.