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