There exists an ancient tomb where many evil rituals have been performed over the years. Rumor has it, the tomb lies in the Vineam woods, and can still be accessed via an eternally burning flame.
Performing a ritual is rather simple. Players must merely enter the tomb and drop items which they wish to sacrifice to the evil forces of the tomb down into the sacrificial pit in the center of the tomb. They must then prove their worth by defeating an army of evil spirits (Vex).
Depending on the value of the item(s) sacrificed, the ritual will have an increasing level and scale up the fight.
Every level the evil spirits grow in number and strength, dealing more damage, more rapidly.
At level five, the cracked stone brick within the arena drops out. Players must be careful to stay on the bridges and the central area of the tomb, or else fall to their death in the pool of lava previously hidden by the floor.
The evil spirits will always target the player with the most health, updating their tally every few seconds. The evil spirits will not kill a player until all of their teammates are also severely injured -- at which point players will be warned that the target of the evil spirit's death is near. The evil spirits will then move in for a kill on the player, unless teammates increase their health or the health of the player being attack.
Upon successful defeat of the evil spirits, players return to the campfire, dazed and confused, but with loot scaled to their sacrifice.