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