Tengoku no Saitai
the Pact is a group of Abandoned that have found a way to link various portions of their beings together, to pool them.
Strength/Power, Willpower, Knowledge, Cunning. There are four Abandoned at the top of the 12 creature link. No one is sure exactly why 12 creatures is such a specific number. All 12 creatures pool the four attributes to the four leaders.
Currently, a Shroe named Kuroiyuki seems to possess the historical knowledge of the Abandoned, and has directed the Pact to stopping THEM, a group of 12 extremely powerful Unseen, and through them gain the Great Redemption.