Here is the full list of all 54 Chronicles of a Dark Lord: Episode II War of The Abyss achievements.
View an alternate game over ending
Completed the game
Defeated Xesis
Found the Developer's Room
Completed Magus' Scion Grid
Found a Level 10 Wisdom Scion at the Garlan Mountains
Found the Skull of Onyus at the Garlan Mountains
Completed the Infernus Ruins area
Defeated Urolus
Defeated the Phaelyrm
Destroyed the final Nexus Tower
Destroyed the first Nexus Tower
Repelled the invasion of Ilian
Defeated Appolly'ione
Destroyed all 5 Teleporters
Retrieved the blood of the Revenoth
Visited Trinity in the Healer's Ward
Kill Lars
Completed Chapter 6
Completed Chapter 5
Found the way to the Inferni Diadem
Completed Chapter 4
Win at least 20 battles on Solara Bridge
Found Diovol's weakness
Completed Chapter 3
Executed Zexor for his crimes
Allowed Zexor to live
Killed a woman in Starfall
Kill Serena
Confine Serena in the Dungeons
Completed Chapter 2
Froze a woman in Ilian Castle
Completed Chapter 1
Miniaturized a woman in Ilian Castle
Killed a woman in Ilian Castle
Informed Tia about her husband's fate
Killed every enemy on the Kisareth-Ilian Bridge
Viewed all of the past events in the Mirror Room
Destroyed a teddy bear
View the Scion Grid Tutorial
Found Gelina's portrait
Transform Serena into a bunny
Completed the Prologue
Defeated Xe'on
Used Lars as a means of execution
Found Shanora's Keepsake
Defeated Shade of Exodes
Killed Milton
Upgraded Riggs or Jesiah to Level 10
Completed the Arena
Recruited Eriadne
Defeated She'dai
Defeated John Sierra
Defeated Erovoxis