Rings of the Horsemen (Omniverse)

The Rings of the Horsemen are important artifacts in the series Power Rangers: Omniverse

History
The Rings of the Horsemen, or also known as the Key to Lucifer's Cage, are rings that each of the Four Horsemen of the Apocalypse wear that allows them to channel their essential abilities, although some powers like teleportation, can still be executed without it on. They prove integral in the Apocalypse. The demon named Brady describes War and Famine's "withered husks" after the removal of their rings. Once combined together, the rings form the key to Lucifer's Cage in Hell. The Archangel Gabriel told Hunter and Kurt this secret, and after acquiring all four rings, the Rangers used them to open the portal of the Cage in Hell.

Lucifer, contrary to what Gabriel thought, was aware of this ability to open his Cage. Nevertheless, he allowed the Rangers to collect the rings since the boys' plan required Kurt to consent to being Lucifer's vessel. Ultimately, Kurt managed to regain control of his body long enough to use the rings to open Lucifer's Cage and imprison Lucifer once and for all.

In Chapter 6 of the series, it was revealed that if a human were to wear one of the rings, they would get a form of the power of the Horseman to whom the ring belongs, until removing it.