Here is the full list of all 34 Domina achievements.
Defeat 24 Regional Champions
Drive a Behemoth Regional Champion to Surrender
Kill 9 gladiators in a single battle with only one man
Unlock All Doctore Special Training in a Single Playthrough
Set 25 men free
Defeat 12 Regional Champions
Achieve 100 Victories in the Arena
Dismember/decapitate 50 limbs/heads
Kill 10 Lions in Combat
Kill a gladiator with a thrown weapon
Achieve 25 Victories in the Pit
Sell 25 men
Surrender 25 times
Defeat 3 Regional Champions
Spill 25000 Units of Blood
Kill a gladiator trapped in a net
Kill a man who is chained to the ground
Spill 15000 Units of Blood
Spill 5000 Units of Blood
1st Decapitation
Achieve victory after breaking free from chains
1st Dismemberment
Draw first blood in 3 battles
Kill a gladiator with a wooden weapon
Achieve 1000 Victories in the Arena
Obtain a Lion to Fight in the Arena
Kill 5 gladiators with a lion
Fully upgrade all equipment for a Retiarius on 3 different men
Fully upgrade all Murmillo equipment on 3 different men
Fully upgrade all Thraex equipment on 3 different men
Defeat a Behemoth Regional Champion with your own Behemoth
Throw a gladiator to his death
Finish the game with final victory
Put to death 25 men