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