Back 4 Blood – Guide to Fighting the Abomination

Warning: Massive spoilers for the finale of Back 4 Blood proceed with caution! In this guide, I’ll show you how to effectively deal with the final boss of Back 4 Blood and recommended cards to help you seize the day!

Fighting the Abomination

Starting Act 4

When you start Act 4, all 15 of your deck’s cards will be immediately played and activated. You get to draw one basic card for stamina, ammo, health, or copper. Copper is absolutely useless in this part of the game so pick the 3 former cards before it that suit your needs.

You’ll also have randomized weapons of Epic (Purple) quality for maximum damage output with randomized high quality mods attached to them. Sidearms and Melee included. So pick out the ones you want that suit your playstyle!

Lastly, you start with several thousand copper (Approx. 2500) to start spending for item upgrades, additional weapons, and accessories. You’ll only get to use the vendor once, so make it count!

Once you’re all geared up, head past the saferoom door.

First Phase

First thing you’ll notice is the wandering Ridden on a small section of street. It’s only then that after you drop down onto it that 4 tentacles will pop out of the ground and need to be destroyed.

The tentacles can only be damaged when they open up their weakspot. Which, in turn, is before and after they attack. They hit incredibly hard and can deal significant damage. However, their range is limited and you can run around them to avoid taking a hit.

Once a tentacle is destroyed, they burrow into the ground and occasionally spew acid in a radius around themselves. A horde is also alerted after a tentacle is gone.

After all four tentacles are destroyed, look around the area carefully for extra supplies to restock or change weapons. Do not haphazardly jump into one of the four holes until your entire team is fully ready or you’ll be alone and at the mercy of Mutation Ridden down below in phase 2.

One good strategy for this phase is to have one teammate deal with the Ridden and hordes while the others focus on the tentacles.

Second Phase

Now you gotta deal with the big bastard himself. The area you fight him in is small and there’s limited supplies compared to above ground.

The main goal here is to destroy the weakspots inside the bugger’s mouth as quickly as possible while Ridden and Mutations constantly spawn. You also got to deal with the tentacles from earlier which do massive damage when they strike you. He’ll also chomp at you if you get too close to his head.

Like the previous phase, he’ll open his mouth with weakspots but the difference being only after he attacks with the tentacles. The tentacles are the biggest threat here. They spew acid and attempt to impale you to the walls. Even after they’re stuck in the walls, they can slam the ground around them dealing massive damage to you.

As before, try to have one person deal with the constant spawns of Ridden while the rest focus on the big guy. Pay extra attention to the tentacles and where they’ll attack. They can be easily dodged if you know where they’re aiming at.

Final Phase

The final boss decides it can’t handle how awesome your team is and decides to run away. Problem is this could be the most difficult phase. You’re slapped with a time limit and if it reaches zero you’ll fail your run. The boss is constantly on the move and you need to constantly position yourself to get its weakspots. As usual, Ridden and Mutations spawn but in unpredictable directions.

Not sure if this is a bug either, but I noticed that if you’re in the wrong spot while the Abomination is moving you could get insta-downed from being crushed so be mindful of your positioning.

There’s weakspots on its body that need to be destroyed as quickly as possible. You’re also going to be constantly on the move and constantly swarmed by Ridden. Teamwork is absolutely imperative here if you want to succeed. Staying together will improve your odds as well.

The weakspots disappear after taking enough damage forcing you to shoot at a different spot. Some of the spots are really hard to get to like on top of him or on his underbelly.

Definitely do your best to get to those weakspots to achieve victory!


The biggest cards you want without a doubt are weakspot damage increases. These will shread the boss like crazy since you can only harm him by shooting his weakspots. I also recommend increasing the damage of your preferred weapon type be it Assault Rifles, LMGs, SMGs, Shotguns, Sniper Rifles, etc. Be mindful of the downsides if you want a bigger bonus!

Stamina, Health, Damage and Trauma Resistance will help immensely with your survivability. The more the better. Sprinting efficiency will probably help against the final phase where you need to be constantly on the move.

Also recommend quick revive cards such as Smelling Salts with Avenge the Fallen and Inspiring Sacrifice if you or your teammates go down. Breakout helps you get out of grabs without having to carry Stun Guns in favor over Defibrillators. Healing Trauma cards also recommended but only if it can be done with First Aid Kits or Defibrillators.

Lastly, any cards that involve gaining copper in any form should not be used since copper at this point is useless. Cards that have copper loss as downsides can and should be used with impunity since their downsides become virtually non-existent here. (Ex. Silver Bullets).

Jan Bonkoski
About Jan Bonkoski 962 Articles
Jan Bakowski aka Lazy Dice, was always interested in gaming and writing. His love of gaming began with The Legend of Zelda: Ocarina of Time (Nintendo 64) back in 1998. He’s been making game guides since 2012. Sharing his gaming experience with other players has become not only his hobby but also his job. In his free time, he plays on Steam Deck.

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