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