UA: Oath of Pontida
When at war, land military units can be purchased at cost of City's strength, disappearing upon peace declaration and converting XP to Gold. Trade routes increase origin City's strength and Production of military units.
UU: Caroz (Great General)
Compared to the unit it replaces it cannot build a Citadel but acts as one when in friendly lands.
In addition, it can be expended in the land of a City State to conduct a Diplomatic Mission that does not yield Gold but a free military unit immediately and every 25 turns (standard speed) as long as that City State is friendly.
UB: Signoria (Castle)
Trade Routes gain +25% range and +2 Gold.
Nearby Forts and Caroz contribute to City's Strength and yield +1 Gold when a unit is stacked on them.
Steam workshop link