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