Each Campaign area ends with a boss guarding the exit. They're the climactic spikes of a run — tanky, heavy hitting, and they summon reinforcements throughout the fight. Clear the campaign chain and the rooftop keeps a few secrets you'll have to uncover yourself.
Your first wall — a colossal Brute that periodically calls in packs of Runners to harass you while it lumbers in. It's slow, so the fight is about not getting pinned between the King and its summons. Kite wide, gun down each Runner pack as it arrives, and chip the King on the way past. Faced right after the fists-only warm-up, so it's tuned as a gentle introduction to boss fights.
A ranged zoner that fires fast multi-shot acid bursts from long range and seeds the arena with extra Spitters. The danger is crossfire — the Queen and her brood pepper you from multiple angles at once. Use the Vat Halls' pillars as cover, break line-of-sight, and dash through the bursts to close and burn her down. Kill the summoned Spitters so the angles don't stack up.
A change of pace: the Warlord is a fast melee charger — the quickest boss in the chain — that hits like a truck and spawns Bombers to corner you. You can't simply outrun it the way you do the slower bosses — you have to use the dash to break its approach and keep obstacles between you. Detonate the Bombers at range so you're never caught between an explosion and a charge.
The original Campaign capstone — a relentless summoner that raises waves of Zombies on a fast timer while throwing projectile bursts. Left unchecked, the arena drowns in undead. This is a DPS-and-discipline check: you need enough firepower (and ideally an area weapon) to clear the adds faster than they're raised, while never letting the projectile bursts and the horde pin you in a corner.
You reach the rooftop, the evac bird is inbound, and the Overseer drops in — a shielded ranged zoner that shrugs off a chunk of incoming damage, hammers heavy projectile volleys, and summons Brood (which split into Spawnlings). It looks like the end of the game — but the rooftop still has more in store, so come into this fight with ammo and health to spare.
A horned ranged overlord that doesn't appear in the Campaign chain but turns up as a boss in Endless mode's generated arenas. Fast for a boss, fires fireball bursts from long range, and summons Archdevils. Same playbook as the other ranged bosses: break line-of-sight, clear the elite adds, and close the distance in dashes.
