Horizon Zero Dawn has many different outfits and weapons to fit your playstyle. If you prefer to have a lighter outfit for more agility, the game has you covered. For those who aren't the quickest, however, there is the Shield Weaver outfit. When it comes to protecting Aloy from the vast array of robots, the Shield Weaver is the best of the best. This is because it essentially soaks up some damage before Aloy actually takes any of her own. It's recommended that you unlock this armor before the final few missions as the final boss can be quite difficult. Horizon's endgame doesn't offer much in terms of challenge, unfortunately.
The way you find the Shield Weaver outfit is through the Ancient Armory side quest. This side quest becomes activated by either picking up one of the five Power Cells for this mission or by finding the bunker to the Ancient Armory. The armory itself can easily be found in the early areas of the game, just southwest of Devil's Thirst.
The quest can only be completed once you find these five Power Cells, which will require some exploration here and there. Luckily, most of them are found throughout the game's main missions. This is a relatively easy side mission, so long as you make note of them early on in the game. You can find each of them with their corresponding missions as you progress. Otherwise, you will have to go back to these areas, which will be very inconvenient.
Here is a guide to finding each Power Cell that will let you unlock the best armor in the game. The list will be in the recommended order as it aligns with the progression of the story.
6 Power Cell #1 - Underground Ruins
The first Power Cell can be found in the original bunker that Aloy fell in as a little girl. This is the only Power Cell that is not found while doing a specific mission, so it's best to find this first. The Underground Ruins will be found just northeast of the All-Mother Mountain. You will see a Ruins symbol where you can set your waypoint to.
Simply make your way down this bunker the same way you did the first time. You'll eventually reach a bunker door. On the right of the door facing it, you will see a formation of stalactites, which are blocking your way in. All you have to do is smash them with your spear and you can make your way in. The Power Cell can be found immediately after walking in.
5 Power Cell #2 - All-Mother Mountain
Right after you complete The Proving main quest, you'll awaken in the All-Mother Mountain. After the cutscenes, you're given control of Aloy to start gathering your belongings. Teersa will ask you to follow her, and she will turn left. Do not go left, instead, keep going straight. If you look off in the distance, you will see a door. The door will be indicated by the glowing red holo lock dial. Head towards that door.
You won't be able to go into the bunker door. Instead, you will see a ventilation duct to the left of it, which you can crouch into. Just make your way through the duct, and you'll eventually find the Power Cell at the very end.
4 Power Cell #3 - Maker's End
Maker's End is the name of the area you'll need to go to. Maker's End is also the name of the mission the next Power Cell can be found in. Keep progressing through the mission, which has you scaling a skyscraper that's been decimated. You will find yourself in Faro's office towards the end of the mission.
In this office, you will see a scalable wall that contains the yellow climbable objects. This will bring you all the way up to the top of the skyscraper. Just follow the path as you climb up. Once you've made your way to the top, you'll find the Power Cell.
3 Power Cell #4 - The Grave Hoard
This Power Cell will be found throughout the main mission titled The Grave Hoard. This one will require the least bit of exploration as it's extremely tough to miss. Keep progressing through the mission, and you will end up having to unlock an ancient door. This requires you to move around four holo lock dials. Once you've finished this puzzle, you will have unlocked the ancient door. Once you enter, the Power Cell will be seen immediately after you walk in.
2 Power Cell #5 - GAIA Prime
The last Power Cell is the trickiest to find. It is found in the GAIA Prime ruin during the Mountain That Fell quest, which is very late in the game. While in the ruins, you'll eventually speak to Sylens in his workshop. Once you're done talking to him, you'll have your next objective to make your way to. You will see a zip-line that you can easily jump onto. DO NOT go down the zip-line just yet.
Instead, go down to the left of the zip-line, which will have a slight drop. Once you've landed, slowly walk towards the edge of the cliff, and you will be prompted to drop down the ledge where you can hang. If you keep moving Aloy to the left, she will start making her way down the yellow climbable objects. Keep following this secret path and you will eventually find a purple lit room. This room contains the final Power Cell, which will be in plain sight upon making your way in.
1 Unlocking The Ancient Armory
Once you've found all five Power Cells, make your way back to the Ancient Armory. Activating the quest will give you directions on how to get there if you forgot. Upon entering, you will need to input two of the Power Cells, which will then light up five holo lock dials. To the right of these dials, you will see a display that shows five different time codes; 1200, 1500, 1800, 2100, 0000. These time codes will be in military time, so you just need to match each dial with the correct time displayed on the right. The dials will act as a clock of sorts where you need to turn them to the correct position.
Here's the correct combination starting from the left: Up, Right, Down, Left, and Up.
This will unlock another room, where the remaining three Power Cells you found can be put into. Like the previous room, this will light up the holo lock dials. To the left, you will see another set of numbers; 90, 270, 360, 450, and 630. These are angles that the dials will need to be set to.
Here is the combination for the next five dials starting from the left: Right, Left, Up, Right and Left.
After you've completed these two puzzles, you can loot the Shield Weaver Outfit Box. Just go to your inventory, open up that box, and you now have the armor. Enjoy!