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