The Rune of Strife

The gnolls have overrun Crossroads and driven out Wolf's Irregulars. The Nexus of Water has ruptured and been invaded by abyssians. The Danse Macabre vies with the Winds of Change. The elemental forces are in conflict as war and strife cover the land.
The Dark Cleric to Rivenhouse uses the energies of the mansion’s manifestations and the stains of War left behind to craft a new holy ground. He collects all the essence of War that has been fermenting for years: Wizard Wars fought on the Haunted Plains, creates by Flame, Cinder and Mechella, the War of the Flame, the contest for the title of Lord of the Wood, the collision between Order and Chaos. All this conflict and violence coalesces wells up like an ulcer and, at the direction of the Dark Cleric, it ruptures. Like when the Circle of War appeared in Kismet's Game, the Dark Cleric floats above the ground. It reaches into a large satchel and grabs a handful of desecrated soil gathered from its foul patron’s holy ground. With spectral limbs it sprinkles the soil about to form a circle. The Dark Cleric who then shapes the town's spiritual cancer into that circle manifesting a foul arena, the Pit of Strife.
Like the Circle of War, any who enter into the Pit of Strife will find themselves trapped in the arena with a foe they must defeat. More often than not, combatants will face those of roughly equal power, but there is a random element to the pit that may mean a pugilist will face an opponent of significantly greater or lesser power. It has been discovered that certain blood rites or battle ceremonies that are performed before entering the pit can affect which foe will be face in combat.
Once in the pit, the only means to leave it is as victor or corpse. Magics to avoid combat, such as Teleport, Calm or Sleep, will not function until the evoker is a hair's breath away from death. Some brave souls choose to enter the pit to hone their combat skills. Some go in hopes of finding the loot on their slain foes. While others are cast into the Pit of Strife by baneful magics such as those that are held in goblin runesticks, Narzynn Chalices or other woodland treasures. Some who enter the Pit of Strife find they are possessed and transformed into some other been, such as goblin shamans, gnoll raiders, human mages, sprite guardians, ravenous zombies or zealous cultists.
Some mages theorize that there are many Pits of Strife that work as trans-dimensional portals. That a Fallenstar combatant faces a foe who is actually a counterpart warrior that entered another pit in a distant place like Cairn, the Forest of the Damned, or the Sprites Realm. A number of templar conjecture that the adversaries that are faced in the arena are actually the spirits of long dead combatants. While, many diviners believe, but cannot magically confirm, that those that enter the pit face their own shadow self, some aspect of their psyche is monstrous, violent or self-destructive. The truth remains to be seen.