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