The Atlantean Compensator

Herald, a 25years old man.
Always found on supernaturals and spirituals.
Finds out that it's more than just a liking.
He undergoes a series of events that he himself wouldn't be able to comprehend.
The Atlantean, with 6 others.
Formed by a mysterious association.
Get trained in order for something they have no clue about.
What are their powers?
Why did they agree?
What kind of world they're living in?
What is there for them to face?
And...
Who are they!