Here's a list of all Rare Champions:

Marian / Engineer
  • Battalion slot: Siege Machines
  • Passive I: Increases the normal defense of your battalion
  • Passive II: Increases Machine damage
Osbert / Engineer
  • Battalion slot: Siege Machines
  • Passive I: Increases the normal defense of your battalion
  • Passive II: Increases Machine health
Walter / Miner
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases Mining capacity
  • Passive II: Increases Mineral Mining rate
Roger / Miner
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases Mining capacity
  • Passive II: Increases Metal Mining rate
Michael / Miner
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases Mining capacity
  • Passive II: Increases Gem Mining rate
Sigurd / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases the normal defense of your battalion
  • Passive II: Increases Infantry damage
Hilda / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases battalion's defense against Fire damage
  • Passive II: Increases Infantry damage
Henry / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases battalion's defense against Frost damage
  • Passive II: Increases Infantry damage
Godfrey / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases the normal defense of your battalion
  • Passive II: Increases Infantry health
Sarah / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases battalion's defense against Fire damage
  • Passive II: Increases Infantry health
Ulric / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases battalion's defense against Frost damage
  • Passive II: Increases Infantry health
Julia / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases the normal defense of your battalion
  • Passive II: Increases Mounted damage
Aubrey / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases the normal defense of your battalion
  • Passive II: Increases Mounted health
Dirk / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases battalion's defense against Fire damage
  • Passive II: Increases Mounted health
Muriel / Officer
  • Battalion slot: Infantry / Ranged / Mounted
  • Passive I: Increases battalion's defense against Frost damage
  • Passive II: Increases Mounted health