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