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