Grail

Income is twice as high, 9000 gold, and a special Grail ability (depends on the faction). I don't remember all the abilities, but here are a few:
Conflux - all spells
Dungeon - all earth spells deal more damage and are more effective
Inferno - each week will be a week of imps and inquisitors
Necropolis - necromancy ability is -% more effective