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