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 Honour Mode
Fane: Return the Eternals to Rivellon
Fane: Embrace this strange new world
Share Divinity with The Doctor
Sebille: Destroy the Mother Tree
Sebille: Serve the Mother Tree
Sebille: Kill the Master
Purge Rivellon of all Source
Share Source with all of Rivellon
Complete the game in Tactician Mode
Submit to the God King
Ifan: Kill Lucian
Ifan: Forgive Lucian
Successfully walk the Path of Blood
Lohse: Banish your demon
Lohse: Embrace your demon
The Red Prince: Become the father of dragons
The Red Prince: Kill the Red Princess
Obtain Anathema
Beast: Ally with the Queen
Beast: Assassinate the Queen
Pray at every altar on the Nameless Isle
Discover the hidden entrance to the Academy
Convince all party members to let you ascend
Learn of the Council of Seven's location from Malady
Set Gareth on a path of vengeance
Use the Curse skill
Destroy every Voidwoken egg in Reaper's Cove
Tame Featherfall
Lockpick your way into Mordus' hidden lair
Become champion of the Driftwood Arena
Escape Dallis' siege on the Lady Vengeance after killing every minion
Craft a grenade
Craft a skill
Craft a scroll
Kill Slane
Kill Radeka
Complete the game in Explorer Mode
Complete the game in Classic 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
Shapeshift into every race
Defeat Adramahlihk
Make a deal with Adramahlihk
Gain the Villain tag
Rescue Arhu
Discover Reimond's Lair
Successfully begin a match in Arena Mode
Successfully begin a Game Master session
Force Dallis to retreat from combat in Fort Joy
Arrive at Arx
Enter The Arena of the One
Convince Alexandar to ally with you
Swear to the Covenant
Enter the Academy
Arrive at the Nameless Isle
Take the ferry to Bloodmoon Island
Kill Andras, the necromantic dog
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
Serve Garvan the tainted stew
Perform successful surgery on Natalie
Correctly answer all of Crispin's questions
Help free Mari from the Voidwoken
Set Gareth on a path of reconciliation
Unlock your second Source Point slot
Receive Dorotya's kiss
Adopt Peeper
Speak to an animal's spirit
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
Equip runes to all of an item's available slots
Rescue Gareth from Braccus' Armoury
Face a higher power
Arrive at the Sanctuary of Amadia
Escort the Black Cat out of Fort Joy
Flee Fort Joy for good
Use your first Source Skill
Kill an enemy using Teleportation
Get caught breaking the law
Remove your Source Collar
Become champion of the Fort Joy arena
Gain the Hero tag
Win a persuasion event
Arrive at Reaper's Eye
Escape the kraken's clutches
Perform a successful theft