those rare upgrades could be enabled if some resource is conected to the city. eg. having connected fire shard to the fort you could have a powerful firewall, a wildling camp in conclave could produce wildling shamans
Good ideas! Wildling shamans are scary in groups!
Water shard creates large areas of stinking mud on the battlefield
A knights of Asok attached to the city creates a sally port that sends a unit of cavalry to defend the city. (trolls and ogres can do the same thing)
Life shard gives all units +2 tactical regen for city sieges.
Air shard gives Guardian wind, 2 shards adds an Air Elemental.
