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