Here is the full list of all 55 The Banner Saga 2 achievements.
Survive with only human Heroes. (Normal or Hard Difficulty)
Survive with fewer than 20 Heroes dying. (Normal or Hard Difficulty)
Survive without using the Horn for willpower. (Normal or Hard Difficulty)
Survive without Recruiting Heroes. (Normal or Hard Difficulty)
Survive all battles on Normal.
Survive in less than 180 minutes for your total turns. (Normal or Hard Difficulty)
Complete the game on Normal difficulty.
Defeat 3 enemies with War Bear.
Complete the game on Hard difficulty.
Complete the game on Hard difficulty level without losing a single battle.
Meet King Meinolf with Rook.
Witness Eyeless possess 10 fallen units.
Break 30 barricades in a single playthrough.
Complete Holfi's Training.
Acquire 3 rank 10 items.
Defeat 3 enemies with Zefr.
Kill 5 enemies while stealthed.
Prevail with Rook against overwhelming numbers.
With 6 Rank 10 units, win a Hard difficulty sparring battle in the Training Tent.
Complete the game without letting anyone in your caravan die to hunger.
Complete the game without ever getting low morale.
Defeat 3 enemies with a Poet.
Meet King Meinolf with Alette.
Build an army of over 600 trained fighters.
Bring 400 clansmen safely into Arberrang.
Reach Arberrang in 100 days or less.
Visit the godstone Lauga.
Fight 32 battles in a single playthrough.
Maintain an alliance with Rugga.
Kill a Sundr.
Bolverk always acts as the Ravens expect.
Reach Oldford with at least 20 Varl following Bolverk.
Visit the godstone Bygglaerer.
Kill 5 in one turn with Cull the Weak.
Visit the godstone Geirraðr.
Complete Sven's Training.
Defeat 3 enemies with a Tracker.
Visit the godstone Vez'nan.
Defeat 3 enemies with a Male Horseborn Teulu.
Defeat 3 enemies with a Female Horseborn Cantref.
Visit the godstone Baldringr.
Defeat 3 enemies with a Slaughterer.
Defeat 3 enemies with a Shieldmaiden.
Defeat 3 enemies with a Wanderer.
Visit the godstone Irynx.
Defeat 3 enemies with an Axe Thrower.
Defeat 3 enemies with a Berserk.
Visit the godstone Aselei.
Import Save Game from Banner Saga 1.
Survive with only female Heroes. (Normal or Hard Difficulty)
Survive using only parties of 4 varl in every battle. (Normal or Hard Difficulty)
Survive all battles on Easy.
Survive all battles on Hard.
Survive without a single Hero dying. (Normal or Hard Difficulty)
Survive Hard Mode without a single reload