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