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