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