Fatalis

While the horns are intact, last-phase fire from Fatalis is a wipe. Each horn break drops that breath toward earlier-phase damage; two breaks bring it back to a survivable fight. Cannons and ballistae can topple it; a Flinch Shot while it is flying or standing lowers the head for more horn damage. At the first nova, get behind the iron shelter before the blast. At the second, pull the rear-gate lever and stay behind the closed door. Later cone novas are survived under the body or off to the side, not in the open field ahead of the mouth. One-shot binders, the roaming ballista, and the Dragonator pin or topple Fatalis so the party can put horn damage in before that last phase turns lethal.