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