How To Unlock Sentinel Armor In Doom Eternal
Your Doomguy is pretty spiffy to begin with, but you might want to change up his look as you go. Switching armor and appearance isn't as easy as it is to do in, say, Animal Crossing: New Horizons, but it's possible. You just need to be vigilant, because the snazzy sentinel armor is closer than you might think.
First, the game will give you the armor if you happen to be struggling with a certain area. If you die continually in a particular location thanks to an especially nasty horde of demons, Doom Eternal will take pity on you and offer you some sentinel armor. Sentinel armor is super reinforced and will thus drastically lessen damage dealt by demons. This isn't the only way to unlock this piece of equipment, however.
Where to find the sentinel armor
If you don't want to suffer for the sentinel armor, then you might be surprised to find it's been under your nose this whole time in the Fortress of Doom. This is where you load into the game, but it still has its secrets. For example, if you go down to the second floor of the Fortress of Doom and keep left through two annoyingly slow doors, you'll find yourself on a broken pathway, a yawning chasm of space beneath you.
Don't let this intimidate you. Just hop on over and you'll find the sentinel armor there. To wear it, you'll need at least two sentinel batteries. You obtain these through various missions or by completing challenges, so once you've got the batteries, return to this secret location to unlock the armor.
See? Simple. There are other appearances and armor throughout the game, including the classic marine and praetor customization options. These are also nestled in the Fortress of Doom, ready and waiting for worthy Doomguys to find. Like the sentinel armor, they take a little patience and careful searching to uncover. Good luck filling out your closet in Doom Eternal!
How to find Sentinel Batteries
Sentinel Batteries are not just cosmetic items — they have the purpose of unlocking new areas in the Fortress of Doom. As DBLTAP explains, you can find Sentinel Batteries in two ways: discovering them within levels, or completing challenges.
Sentinel Batteries appear on the map as question marks, and can be seen only when you're near their location. In the levels, they have a blue light that makes them easy to spot. These collectibles are often located in hidden areas, which may require to break a wall or vent for access. To get some of the batteries, you'll need all three keys.
According to IGN, the levels that contain Sentinel Batteries are Exultia, Cultist Base, Doom Hunter Base, Super Gore Nest, ARC Complex, Mars Core, and Taras Nabad. When you can't find the batteries in a level, don't despair: you can get more by doing challenges!
After level three, each level has three challenges, which unlock several types of collectibles, including Sentinel Batteries.