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