Here is the full list of all 49 Demonicon - there are The Dark Eye achievements.
Passed a Talent test
Killed the cannibal in Moloch Mountain
Received the Gift in the tutorial
Learned Chain of Blows
Spared the cannibal in Moloch Mountain
Achieved a chain of 12 blows and triggered Demonic Fever
Became member of the City Guard
Became member of the Kreutzer Cartel
Convicted and killed Falk
Spoken to Borbarad's Council of the Dead
Defeated the overpowering Heshthot in the market
Caught the summoner in the Praios temple
Killed Borak the Bruiser
Gave Ulev the talisman
Gave Genla the talisman
Defeated Ghamat and the Plague Maw
Defeated the Iribaar's Lily and yourself
Banished guards
Banished bandits
Killed Cassio and sacrificed her blood
Taifelel defeated
Denied Calandra
Slept with Calandra
Introduced the Catechism to the New Church
Destroyed the New Church's Catechism
Defeated Azaril
Freed father from imprisonment
Sacrificed yourself as First Paladin
Sacrificed Calandra as First Paladin
Returned to Moloch Mountain
Reached Level 7 in one Adventure talent
Led the Fernfielders to their fate
Achieved a chain of 24 blows
Completed 5 battles without a scratch
Cast 200 Gift spells
Used 200 combat moves
Successfully dodged two hundred times
Reached Mastery Rank Four in one talent
Raised an attribute to its maximum
Played Demonicon through without using a single healing potion
10 potions or poisons used
250 potions or poisons used
Killed 10 enemies solely with Ranged Weapons
Acknowledged Seghal and thereby chosen the Gift
Acknowledged father and thereby chosen humanity
Played Demonicon through in Nether Hellish difficulty
Played Demonicon through in Hard difficulty
50 potions or poisons used
Suffered the pain of Rondra's prescence