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