Carry out 100 combos in combat.
To unlock this achievement you must execute at least 100 combat combos when facing opponents. Combos are learned as you level a specific weapon type, with 3 for axe, 3 for mace, and 10 for sword.
You can monitor your progress by navigating to: Player > Statistics > Combat > Combos performed.
Note: If you are having trouble executing combos when facing enemies in the heat of battle, you can speak with Captain Bernard and practice with him in a safe environment.