Here is the full list of all 49 Nights of Azure achievements.
Collected all achievements.
Completed 300 tasks.
Defeated 10,000 enemies.
Actualized 80 Servans.
Arnice achieved her max level.
Collected all items.
Viewed an extra ending.
Cleared all Arena tasks.
Transformed into Nightmare form.
Arnice equipped Glass Blade and cleared a battle.
Arnice equipped Hamelin's Pipe and cleared a battle.
Completed 100 tasks.
Actualized 40 Servans.
Collected all Servans.
Defeated Christophorus.
Executed trades all over the world.
Defeated Mistral.
Viewed an ending.
Defeated Ludegert.
Maxed out a Servan's level.
Defeated Corrine.
Transformed into Armor form.
Defeated Blueblood Dragon Mavelus.
Achieved 500-Chain.
Achieved 300-Chain.
Summoned Servans 1000 times.
Defeated Blueblood Maiden Milaya.
Cleared half of Arena tasks.
Transformed into Rabbit form.
Collected 50% of items.
Executed trades in half of the world.
Defeated Blueblood Count Rosier.
Executed a trade for the first time.
Collected 50% of Servans.
Defeated Blueblood Cavalry Carousel.
Defeated 1,000 enemies.
Summoned a Servan 100 times.
Transformed into Phantom form.
Gave 1000 orders to Servans.
Cleared first Arena task.
Completed first task.
Gave 100 orders to Servans.
Defeated Blueblood Dragon.
Transformed into Demon form.
Achieved 100-Chain.
Actualized a Servan for the first time.
Defeated 100 enemies.
Summoned a Servan for the first time.
Gave an order to a Servan for the first time.