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