Here is the full list of all 35 Brigandine The Legend of Runersia achievements.
Clear Main Mode as the United Islands of Mirelva.
Clear Main Mode as the Republic of Guimoule.
Clear Main Mode in 40 seasons or less.
Attempt Challenge Mode for the first time.
Choose to battle Aurora and Endorian.
Register 10 event types in the Records of History.
Choose to suppress the Incarnation of Rune.
Clear Main Mode as the Norzaleo Kingdom.
Clear all Lands of Distorted Mana Showers.
Deal 500 or more damage to an enemy unit in a single attack.
Clear 5 Lands of Distorted Mana Showers.
Equip any knight or monster with items that trigger a 3★ set bonus while playing Main Mode.
Activate the maximum number of elements (9) for any knight or monster.
Clear a Land of Distorted Mana Showers for the first time.
Completely defeat all enemy nations.
Completely defeat three enemy nations.
Successfully repel an enemy invasion.
Perform a Revive Summon using a Revival Stone.
Completely defeat an enemy nation.
Capture four or more enemy bases in a single season.
Invade an enemy base from two or more sides and defeat them in battle.
Find a 3★ equipment or item during an exploration quest.
Win a battle without a single wounded knight or defeated monster.
Recruit an unaffiliated knight during an exploration quest for the first time.
Summon a special rare monster.
Invade an enemy base and defeat them in battle.
Obtain every other achievement.
Clear the game on Hard Mode.
Clear Main Mode as the Shinobi Tribe.
Clear Main Mode as the Holy Gustava Empire.
Clear Main Mode as the Mana Saleesia Theocracy.
Register 20 event types in the Records of History.
Register all events in the Records of History.
Achieve continental unification in Challenge Mode.
Acquire a Strategy Score of 30,000 in Challenge Mode.