Nekron

From the Orange Power Ring of Avarice we move to the Black Power Ring of Death and its creator, Nekron. And extra-dimensional being living in the vicinity of hell, he saw the universe of the living when Krona the immortal was banished "“ the paradox of having an immortal in the land of the dead further enhances his desire to take over the newly discovered universe.

The power of Nekron is so huge that, at one time, he even managed to trap the Anti-Monitor on a distant planet. What did Nekron intend to do? Obviously, to kill life itself, him being the embodiment of death. So strong he is that he managed to latch Black Rings on almost all the major Justice League members, including Superman and Wonder Woman. Only Hal Jordan and Barry Allen escaped, since the latter time-jumped 2 seconds into the future.

His powers are limitless "“ nonetheless, he does need a link between the living universe and his unliving realm, which is usually a rift or a mortal (Black Hand, the leader of the Black Lantern Corps, one of the mightiest Lanterns in the universe).