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