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