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