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