Check period, winner and seal before finding Mammon.
The winning cabal acquires a new seal with at least 35% of its members choosing it; retaining its previous seal needs at least 10%. These are member choices, not Seal Stone scores. Thus 20% can retain Gnosis but cannot acquire it anew.
During the Seal Effective Period, Gnosis must belong to the winning cabal: its members can enter the six Catacombs and find the roaming Blacksmith Of Mammon. He is absent during competition.
Avarice instead enables the Merchant Of Mammon, also called Trader of Mammon, in the eight Necropolises during seal effects. He roams; the owning cabal has access.
During competition, registered Dawn/Dusk members can enter these dungeons; the Mammon NPCs remain unavailable.
During seal effects, the losing side and players who have not rejoined can pay Adena at an entrance Gate Keeper Ziggurat to reach the Dimensional Rift. This exception does not grant access to Mammon or unrestricted dungeon hunting.