In the cabal warfair cabals, maybe make it able to buy a gnomish seige tank, where the inducted person types a command like "Operate tank" or somthing, and if there are no garrisoned units inside of the bastion, a player from the other cabal is online, and the player is at the bastion, maybe have it do a big deal of damage to it.
Aabahran
the forsaken lands
abandon hope, all ye who enter