For those who fell in love with 2016’s Doom release, and are excited to see how things have changed in Doom: Eternal, you’re in for a few surprises. However, the look of the updated Doom guy armor in the 2016 release resonated with a lot of fans. It was a modern take on the classic armor. For those who loved it, the appearance is available in Doom: Eternal.
You can unlock it from the Fortress of Doom hub location. You have to find it, though. It’s on the second floor. From the primary area on the upper location, go to the right side down the stairs. Continue down to the second floor, and from the primary area on this floor, go to the left again and you will find two doors you need to go through. On the other side of the second door, there’s a small open area with a bridge connecting to another location. There, you can unlock the Praetor armor.
However, you need to have two free sentinel batteries to access it. You can acquire these from any of the missions anywhere in the game on any level. There is a handful hidden on some of the levels, but you can also earn them by completing the three challenges of any mission. After you have your spare two batteries, return to the unlock location to use them, and you can now freely use the armor. To wear it you need to return to the main menu of Doom: Eternal and choose it in the customization section for the Slayer.
There are a handful of customization skins you can wear and change into in the game, such as the Classic Marine Armor, which you can also unlock on the Fortress of Doom.