Dark and Ominous:
* The Night Terrors
* The Shadow Walkers
* The Whispering Wind
* The Blackened Hearts
* The Raven's Claw
* The Crimson Dawn
* The Obsidian Order
* The Silent Watchers
* The Unseen Hands
Mystical and Supernatural:
* The Blood Moon Coven
* The Ancient Ones
* The Spirit Summoners
* The Demonic Pact
* The Whispering Dead
* The Wailing Ghosts
* The Soul Reavers
* The Phantom Legion
* The Witch's Circle
Brutal and Violent:
* The Iron Fist
* The Bloodhounds
* The Skull Crushers
* The Butcher's Guild
* The Crimson Hand
* The Broken Bones
* The Fury Unleashed
* The Warlords
* The Slaughterhouse
Mysterious and Intriguing:
* The Order of Shadows
* The Serpent's Tongue
* The Unseen Alliance
* The Veiled Ones
* The Crimson Oath
* The Silent Watch
* The Crimson Veil
* The Whispering Legion
* The Obsidian Eye
Remember:
* Consider the setting and theme of your story. A name that works for a medieval fantasy clan might not be suitable for a modern horror story.
* Think about the personality and motives of the clan. This will help you choose a name that reflects their nature.
* Don't be afraid to experiment! Try out different combinations and see what sounds best to you.
Happy writing!