Here is the full list of all 44 Champions of Anteria achievements.
Build 20 fortifications
Build 10 fortifications
Defeat the Dark Cult
Conquer 3 territories belonging to the Dark Cult
Conquer 1 territory belonging to the Dark Cult
Defeat the Broken Crown
Conquer all map territories
Defeat the Frostbeards
Unlock all sectors of the kingdom map
Repel 10 enemy attacks in a defense scenario
Build 5 fortifications
Conquer 3 territories belonging to the Broken Crown
Conquer 10 enemy territories
Conquer 3 territories belonging to the Frostbeards
Build 20 trading posts
Conquer 10 territories
Defeat the Dune Tribe
Conquer 5 enemy territories
Repel 5 enemy attacks in a defense scenario
Conquer 3 territories belonging to the Dune Tribe
Build 1 fortification
Build 10 trading posts
Conquer 1 territory belonging to the Broken Crown
Conquer 5 territories
Conquer 1 territory belonging to the Frostbeards
Build 5 trading posts
Conquer 1 enemy territory
Conquer 1 territory belonging to the Dune Tribe
Unlock 4 sectors of the kingdom map
Repel 1 enemy attack in a defense scenario
Build 1 trading post
Conquer 1 territory
Unlock 1 sector of the kingdom map
Finish the tutorial adventure
Start a game
Win the game in under 40 turns
Win the game without losing a territory
Win the game without losing a single adventure
Beat the game in Ironman Mode
Beat the game in Ironman Mode in under 40 turns
Win the game in Ironman Mode without losing a territory
Win the game in Ironman Mode while owning all territories
Beat the game in Ironman Mode without losing a single adventure
Win the game without any Champion dying