WARNING: This guide contains spoilers for the story of Borderlands 4
Bio-Bulkhead is one of the main story bosses the player will encounter on the way to confronting Idolator Sol.
When news breaks that Idolator Sol intends to unleash a bio-weapon against the Fadefield rebels, Zadra and the Outbounders send the player to infiltrate his nearby facility. There, they uncover a grim scheme: innocent lives are to be sacrificed to forge an almost indestructible armor. Before the truth can spread, the player must confront its first abomination - a raging creation of the Order known as the Bio-Bulkhead.
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Bio-Bulkhead is located at the end of the Synthetic Nave in The Fadefields.
In order to gain access to him you will need to have completed the One Fell Swoop mission.
How to Beat
Bio-Bulkhead has one Armor health bar separated into 4 segments. He has one move set that does not change throughout the fight.
FIGHT TLDR
Pick up Locust Cannisters located against the walls of the main section of the arena.
Throw Locust Cannisters at the boss to remove immunity.
Attack boss while vulnerable.
Repeat when immunity regenerates after each segment of the health bar is depleted.
Mechanics
Ground Slam
What Happens:Bio-Bulkhead jumps in to the air and crashes down, creating a puddle of ⚡Shock and sending a shockwave from his location.
What to do: Keep your distance to avoid getting hit by the initial crash, then jump over the shockwave.
Dodge the bunny hop, jump the shock wave.
Leap
What Happens: Leaps towards the player, dealing damage and leaving a puddle of ⚡Shockon the ground.
What to do: This only happens when Bio-Bulkhead is far from the player and serves as its primary gap closer. Dodge away from the impact.
He started at the blue puddle. Don't underestimate his range.
Arc Slash
What Happens: Sends out a ranged arcing wave of energy that curves outwards and then inwards towards the player, dealing damage.
What to do: If the boss casts this from up the stairs you can go down and duck under it. If the boss casts this from down the stairs, you can go up and jump over. Alternatively, dash at the last second.
If you go upstairs, you can jump these!
Ram
What Happens: Runs towards the player and inflicts a heavy damage knock back.
What to do: Make sure you aren't out of stamina as the ram is about to connect so you can dash back at the last moment. Line of sighting the boss will also interrupt the charge.
Never get too close to the angry Bulkhead.
Impale
What Happens: Waves of spikes surge from the ground towards the player, dealing damage
What to do: They are slow and telegraphed - so long as there is decent distance between yourself and the boss then you can simply sidestep them. You may also jump over them.
Jumping and dashing sidewards is enough to dodge these.
Tips & Tricks
Bio-Bulkhead is entirely Armor, meaning he takes extra damage from 🟢Corrosive and ❄️Cryo, and less damage from 🔥Incendiary, ⚡Shock, and ☢️Radiation
The arena has two main levels: upstairs and downstairs. Most of Bio-Bulkhead's abilities can be dodged by staying on a different level to the boss.
The adds can be kept alive to give easy Second Winds.
