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