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