Nexus Stone

In Reality Z-25 31-H, the Nexus Stone was a powerful gem which granted Nexus Girl her powers.

It was Nexus Girl's sole inheritance from her mysterious deceased parents, believed to have been alien scavengers from Proxima Centaury. It granted Nexi her “superpowers” when she wore it in her tiara. She believed it channeled “a primal magic power from the universe itself”, (PROSE: Nexus Girl Bio) the Nexus Power, which allowed her to call upon other realities and swap elements between them, as well as teleport herself and others, although the latter took a lot of power and concentration.

In truth, the Stone actually transmitted a fraction of the power of the true Nexus Stone located in Hell, which was under the control of Duchess Valmorri. She discovered the truth when Valmorri redirected her teleportation of herself and her friends to Hell, where she took the Stone from her and also talked her into giving herself up before teleporting the rest of the heroes back to the mortal realm. (COMIC: Kate Five vs Symbiote - Chapter 6)