Great One (aka. Black Mass) is a moniker of an unnamed mysterious entity that confirmed as true main antagonist of tie-in story called Truth Behind The Salem Witch Trial, where it was revealed that it was the mastermind behind the Salem Witch Trials. It, along with it's manifestations, are referred by Lemurians and Atlanteans, their worshippers, as Great Old Ones.
After centuries passed, Great One began to prepare its' return to the world, where it's influence was felt by Dr. Griggs and Sam Twoflower the snow fairy during the said infamous Witch Trials, where through it's manifestations, Black Hydra, triggers Salem Witch Trials by possessing innocent people, which one of them is Abigail Williams. Great One also have responsible for the creation of Morganians as well.
Background
From what mentioned in Raido's assignments about the lost civilazation called Lemuria that recorded in Augustus Le Plongeon's works, Great Old Ones was responsible for bringing Lemuria to it's glory. The same influence also spread through the following civilazation that born after Lemuria, Atlantis, that appeared at the same moment where Lemuria in it's golden age. Both ancient civilazations worshipped Great Old Ones as their Gods. Great Old Ones also introduced them supernatural powers, which later reinvented as magic.
However, after learned about The Great Old Ones' true nature and also their weaknesses, both civilazation began a revolution where they uses weapon that can banished, if not truly destroy all Great Old Ones as the cost of their great achievements.
Personality
The Great One is presumably amoral entity that too alien for humanity to understand as much as it's nature, just like majorities of entities within H.P. Lovecraft works, or at least that was it seemed, given that it's influence are what inspired Lovecraft for his works.
Powers and Abilities
Great One' powers are remain mystery, but implied to be God-like. It was capable to create the extension of itself that referred as Creatures of Darkness, where the most famous of these beast is Black Hydra that greatly resembles Hydra.
It's nature also too great for mortals to bear without affecting their sanity, though not apply for those with blood of magical creatures that runs through their veins like the snow fairy Sam Twoflower.
Trivia
- When Abigail manifests Black Hydra's heads around her body, the manner they manifests are reminiscent with how Jackie Estacado from The Darkness series manifests tendrils and serpent heads.
- Great One, along with it's manifestations, were inspired with collective cosmic entities of the same name in H.P. Lovecraft's works.