Cassius Morten, the Traitor, caps Chapter 6 and the Calphade Castle assault. The challenge is not only the boss himself, but the long battlefield chain before him.
Chapter 6: Cracks in the Shield. This Bosses entry standardizes the encounter notes so readers can quickly see where the boss appears, how it is triggered, what makes it dangerous, and what the victory means.
Where It Appears
Chapter 6: Cracks in the Shield
Trigger Mechanism
Triggered at the end of The Unyielding Shields after the Calphade Castle push.
Boss Traits
Strong melee strings, battlefield pressure, and limited room after a long warfront route.
Reward or Story Clue
Defeating Cassius lets Kliff light the Calphade beacon and close the chapter’s warfront victory.
Quick Tips
- Enter with healing prepared.
- Watch the first full attack string before committing to long combos.
Route Flowchart

Screenshot Walkthrough





Reach Cassius
Push through Calphade Castle with your allies and avoid burning all consumables on regular soldiers. The final chase and boss fight arrive after several combat objectives.
Boss Strategy
Cassius uses strong committed attacks and pressure strings. Wait until a full sequence ends before countering, and avoid assuming every stagger is safe.
After the Fight
Follow the objective to the Calphade Beacon. Lighting it completes the battlefield victory and points the Greymanes toward the decision to retake Pailune.
Quick Tips
- Restock before The Unyielding Shields.
- Clear ranged soldiers before dueling elites.
- Save emergency healing for the final third of the fight.