Here is the full list of all 97 Divinity: Original Sin 2 achievements. It takes around 200 hours to unlock all of the achievements on Windows.
Escape Dallis' siege on the Lady Vengeance after killing every minion
Complete the game in Honour Mode
Force Dallis to retreat from combat in Fort Joy
Pray at every altar on the Nameless Isle
Complete the game in Tactician Mode
Share Divinity with The Doctor
Beast: Ally with the Queen
Beast: Assassinate the Queen
Make a deal with Adramahlihk
Successfully walk the Path of Blood
Swear to the Covenant
Convince Alexandar to ally with you
Sebille: Destroy the Mother Tree
Sebille: Serve the Mother Tree
Sebille: Kill the Master
Destroy every Voidwoken egg in Reaper's Cove
Set Gareth on a path of vengeance
Learn of the Council of Seven's location from a higher power
Unlock your third Source Point slot
Tame Featherfall
Learn of the Council of Seven's location from Malady
Escort Saheila outside without fighting the Lone Wolves
Kill Slane
Escort the Black Cat out of Fort Joy
Purge Rivellon of all Source
Discover the hidden entrance to the Academy
Lohse: Embrace your demon
Use the Curse skill
Submit to the God King
Ascend to Divinity
Fane: Return the Eternals to Rivellon
Ifan: Forgive Lucian
Ifan: Kill Lucian
Complete the game in Explorer Mode
Complete the game in Classic Mode
Fane: Embrace this strange new world
Share Source with all of Rivellon
Defeated the Kraken
Gain entrance to Lucian's Crypt without following the Path of Blood
Persuade Toyseller Sanders to give you his amulet
Successfully begin a Game Master session
Successfully begin a match in Arena Mode
The Red Prince: Kill the Red Princess
Lohse: Banish your demon
Defeat Adramahlihk
The Red Prince: Become the father of dragons
Rescue Arhu
Obtain Anathema
Discover Reimond's Lair
Craft a scroll
Craft a grenade
Arrive at Arx
Enter The Arena of the One
Enter the Academy
Convince all party members to let you ascend
Arrive at the Nameless Isle
Awaken the corrupted Ancestor Tree on Bloodmoon Island
Serve Garvan the tainted stew
Learn of the Council of Seven's location from The Advocate
Take the ferry to Bloodmoon Island
Unlock your second Source Point slot
Become champion of the Driftwood Arena
Get caught breaking the law
Lockpick your way into Mordus' hidden lair
Craft a skill
Set Gareth on a path of reconciliation
Perform successful surgery on Natalie
Kill Andras, the necromantic dog
Correctly answer all of Crispin's questions
Speak to an animal's spirit
Adopt Peeper
Receive Dorotya's kiss
Meet Meistr Siva
Help free Mari from the Voidwoken
Gain the Hero tag
Arrive at Reaper's Coast
Enter the Hall of Echoes
Escape Dallis' siege on the Lady Vengeance without killing every minion
Gain the Villain tag
Take command of the Lady Vengeance
Welcome Tarquin to the Seekers' service
Defeat Alexandar in Fort Joy
Equip runes to all of an item's available slots
Become champion of the Fort Joy arena
Kill Radeka
Kill an enemy using Teleportation
Face a higher power
Remove your Source Collar
Rescue Gareth from Braccus' Armoury
Arrive at the Sanctuary of Amadia
Win a persuasion event
Use your first Source Skill
Flee Fort Joy for good
Arrive at Reaper's Eye
Escape the kraken's clutches
Perform a successful theft
Shapeshift into every race