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