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