You’ve finally reached the Southern Terminus Range in Borderlands 4, you’re feeling like a total badass with your new purple-tier gear, and then you hit a wall. A literal, shield-regenerating wall named Immortal Boneface. If you’ve spent the last twenty minutes unloading every single bullet in your backpack into this guy only to see his health bar snap back to 100% in a blink, you aren't alone. Honestly, half the community thinks the game is fundamentally broken right now.
The Immortal Boneface BL4 encounter (referring to his appearance in Borderlands 4) has become the single most frustrating checkpoint for players trying to push into the higher Ultimate Vault Hunter (UVH) tiers. It isn't just a "git gud" situation. There is a specific mechanic at play here, mixed with a very real bug that Gearbox has been chasing since the Bounty Pack 1 update.
The Boneface Mechanics: Why He Won't Die
First, let's look at how this fight is supposed to work. You aren't just fighting one guy. You’re fighting the Meathead Riders duo: Saddleback and Immortal Boneface.
Saddleback is the big guy. Boneface is the one riding on his back. As long as Boneface is hitched to Saddleback, he is completely invulnerable. You can shoot him with a rocket launcher or tickle him with a fire SMG; it doesn't matter. The game won't even register the damage.
The Transition Phase
Once you chew through Saddleback’s armor and health, Boneface dismounts. This is the moment his name is supposed to change to The Not-So-Immortal Boneface. The joke is that he’s actually a total pushover once he’s on his own feet. Or at least, he was at launch.
In the current state of the game, players are finding that even after Saddleback is a pile of loot on the ground, Boneface keeps his "immortal" status. His shield regeneration rate is tuned so high that unless you are hitting him with frame-perfect burst damage, he heals faster than the bullets can travel. It’s basically a DPS check that most casual builds simply cannot pass.
👉 See also: Tarkov Healthcare Privacy Part 1 Explained: The Survival Guide
Dealing With the "God Regen" Bug
If you’re stuck on UVH3 or UVH4 trying to unlock the next difficulty tier, you’ve probably seen his shield refill in less than a second. It's annoying. Actually, it's beyond annoying—it's progression-blocking.
Proven Community Fixes
Since we’re waiting on a permanent patch from Gearbox, the community has found a few ways to "force" a win against the Immortal Boneface BL4 encounter:
🔗 Read more: Pokemon TCG Pocket Memes: Why Your 1% Luck Is Actually Normal
- The Stickies Method: If you're playing as Rafa, use the Peoples Kaosen or any Jakobs weapon with a high sticky count. The trick is to load him up with as many stickies as possible before they detonate. Since the regen kicks in after damage is taken, a single massive burst of 20+ stickies exploding at once can bypass the regen cycle entirely and one-shot him.
- The Cliff Tactic: Some players have found success by literally knocking him off the arena. If you can bait him near the cliff face in the Cuspid Climb area, certain grenades with high knockback (like the Torgue "Slippy" variants) can send him into the abyss. You’ll still get the kill credit, though you might have to jump down to grab the loot if it doesn't respawn at the Lost Loot machine.
- Ordinance Amon Build: Amon users are having the easiest time here. By using the Red Tree and stacking "Stored Damage," you can unleash a Molten Hammer strike that deals millions of damage in a single frame. This is currently the most consistent way to "melt" through the bugged shield.
Recommended Loadout
Don't walk into The Old Scrape Drill Site with just anything. You need a loadout that focuses on Shock damage for the shield and Incendiary for the health.
- Shock SMG/Shotgun: A Maliwan with a beam splitter is ideal for the initial shield strip.
- The Hellwalker: Surprisingly, Boneface himself drops this. If you managed to get one earlier, the raw burst of a Jakobs shotgun is your best friend here.
- Amp Shields: Use an Amp Repkit. You need that first shot to do as much heavy lifting as possible.
Is It Worth the Headache?
You might be wondering why anyone bothers farming this guy if the fight is such a mess. The answer lies in the loot table. Immortal Boneface is the dedicated drop source for the Lucian’s Flank and the War Paint Repkit.
Lucian’s Flank is a Vladof Assault Rifle that returns 2 ammo to the magazine on every critical hit. In a game where ammo consumption is a constant battle, a gun that essentially has an infinite magazine is a godsend for crit-heavy Vex or Rafa builds. Even with the current 1-second internal cooldown on the ammo return, it’s still one of the best mobbing tools in the game.
Steps to Take Right Now
If you are staring at a full health bar and a "Game Over" screen, here is exactly what you should do:
- Check your UVH Level: If you are on UVH3 or higher and don't have a "meta" build, consider dropping the difficulty down to UVH1 just to clear the mission and get the unlock. You can always come back to farm him later.
- Optimize for Burst, Not Sustain: Sustain damage is useless against a bugged regen. Swap your rapid-fire SMGs for high-damage single-shot weapons like Snipers or Launchers.
- Use Moxxi’s Big Encore: If the boss glitches out and disappears (another common issue), head back to the entrance and pay the credits at Moxxi's machine to reset the encounter without reloading the entire map.
- Watch the Patch Notes: Gearbox has acknowledged the "Not-So-Immortal" shield bug on their support forums. Keep an eye out for any hotfix that mentions "regeneration scaling" or "Meathead Riders boss adjustments."
Beating Boneface right now isn't about having the most skill; it's about out-mathing the glitch. Use high-burst, single-instance damage to bypass that shield regen, and you'll have your UVH4 unlock in no time.