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