Champion

Champion units or Super Units represent some of your civilizations most elite and powerful units, they are often similar to Citizen Soldiers and especially their Elite Promotions but much better. They are much more expensive often requiring Metal in place for food, and available much later in the City Phase. Being elite professional soldiers, they cannot perform any gathering or construction at all simply existing for combat and gain no promotions. They're either powerful but costly units that can be used to deal with civilization weaknesses or exist as a unique super unit that personifies the key traits for your civilization, and provide opportunity for unique tactics exploiting this.

They can be either trained in a champion specific building like the Gymnasion for Hellenes type civilizations or found more typically available from your Fortress, in addition with certain technologies you may be able to allow the Barracks to train champion units.