Here is the full list of all 40 Wings of Vi achievements.
Find a secret.
Beat Rubi in the obstacle course race.
Read all the stories in the Floating Keep library.
Make all the birds in Vi's home fly away.
Watch over the broken bridge.
Defeat Myougi.
Defeat Myougi without taking any damage.
Defeat Myougi having done maximum damage to her each time she deactivates her shield (4 damage).
Defeat Pr'Gora.
Defeat Pr'Gora without taking any damage.
Defeat Electram.
Defeat Electram without taking any damage.
Defeat Amethyst.
Defeat Amethyst without taking any damage.
Travel below each platform during the first minecart sequence.
Talk to a person who hid themself in the caves.
Defeat the Dark Annihilator.
Defeat the Dark Annihilator without taking any damage.
Defeat the Dark Annihilator without letting any bombs touch the floor.
Reach the upper platform in the underwater area in Sinister Grotto.
Beat the last segment in the Sinister Grotto while having defeated all spawns of Terravine along the way.
Defeat Terravine.
Defeat Terravine without taking any damage.
Defeat Terravine with at least one minecart left in the room.
Defeat Kratarac.
Defeat Kratarac without taking any damage.
Defeat the Ancient Constructs.
Defeat the Ancient Constructs without taking any damage.
Defeat the Ancient Constructs only enraging one of his three heads.
Defeat Myougi again.
Defeat Myougi again without taking any damage.
Defeat the Twin Orcs.
Defeat the Twin Orcs without taking any damage.
Defeat Azurel.
Defeat Azurel without taking any damage.
Unlock all weapons.
Defeat Jeh'Oul.
Defeat Jeh'Oul without taking any damage.
Defeat Supreme Jeh'Oul and save the world.
Defeat Supreme Jeh'Oul without taking any damage.