Black Priests

The Black Priests are a group of extremely powerful modern age villains from Marvel comics, acting as major antagonists to many heroes and villains alike - connected to the concept of universal incursions this group are a collective crisis-level threat in their own right but have mostly faced off against the Avengers as a whole.

History
The Black Priests are a society of telepathic creatures who function with a hive-mind, they travel across the multiverse to ensure that incursions are not stopped : in Marvel cosmology an incursion is when two parallel worlds collide, causing the destruction of one world in the process. While incursions are a natural part of the multiverse they are obviously cataclysmic events that cause the eradication of entire civilizations - the Black Priests are a relatively new and enigmatic threat who actively seek to ensure such cataclysms do not get stopped by heroes, science, magic or other means : they will even go as far as killing entire cities in order to ensure a "dying" world is unable to stop its destruction. They are also extremely secretive and will hunt down and kill any who they feel endangers exposing too much on their actions and origins.

Appearance
Despite the name of the group Black Priests dress in red robes and have their faces hidden under elaborate golden masks with a single eye in the middle.

Abilities
The Black Priests are a collective multiversal-level threat, possessing formidable psychic powers as well as a hive-mind : they can easily travel across dimensions and time, they seem to track down incursions and can emit sufficient energy to effortlessly wipe out entire cities without any sign of strain or discomfort.

Their scale of power is at minimum around that of a mid-tier cosmic-enhanced being such as Silver Surfer, if not significantly stronger : due to their secretive nature and homicidal tendencies in defending such secrets their true power level has yet to be fully explored.

Trivia

 * the Black Priests function similar to entities such as DC's Monitors or Marvel's Celestials, as well as the Evolutionaries - all of who view genocide as acceptable means to keeping "order" in the multiverse.
 * the Black Priests singular eye motive, as well as their hive-mind mentality, is similar to the DC villain Brother Eye - though they are far beyond the powers of Brother Eye, being multivseal threats.
 * the single eye is also very similar to that seen in the Eye of Agamotto, though it is unlikely they have connections to the Vishanti (who are usually a neutral force, while the Black Priests are obviously more evil aligned)