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