- Use Staggering Strike 5 times
- Don't get knocked down
The apothecary gave you the location of the rest of the stash that he left for Mirabeau’s killer. Head to the location to begin this mission and then use Eagle Vision to track the "scent" of the killer to the nearby cathedral. After a scene climb the left pillar and make your way to the roof to find the killer, Bellec himself.
The fight against Bellec takes place across four stages, each more aggressive than the next with Bellec going from standard attacks to heavy attacks and then bombs.
The best strategy is to use your Smoke and Stun Bombs to allow you to create long combos and Staggering Strike to knock Bellec off balance. Watch out for when Bellec drops his sword and screams because that means he’s going to use Staggering Strike himself, so make sure you roll away or use Staggering Strike to create a "tie". It is best to play it safe until you learn Bellec’s attack cues so that you don’t fail the second optional objective.
Once you deplete Bellec’s health you’re forced to assassinate him for a scene.