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