The Resident Evil 4 Remake sword puzzle can be found in the castle's treasury once you've paired up with Ashley and have fought off the Garrador in the dungeon. Once inside, you'll see four metal engravings of knights with swords and a locked gate with three symbols on it to your left.
To solve the sword puzzle, you need to open this gate through a combination of pulling cords and shooting symbols, before retrieving the bloodied sword inside to arrange in the mural of metal knights. So, here's how to activate the symbols to open the gate and get the blade so you can continue your travels through Salazar's castle.
Unlike the combo lock where you need to search a book of clues or the puzzle where you have to locate Hexagon pieces, everything you need is located in the room with you.
The first step in solving the sword puzzle is getting the bloodied sword. To do that you need to open the gate with the three symbols. Nearby, you'll see a gong with a stag symbol on it and a cord you can pull to activate it. Once you do, the stag symbol on the gate will start glowing. Now, you need to aim through the bars of the gate and shoot the eagle and snake gongs to light the other symbols, opening the gate so you can get the sword from the statue.
After this, you'll need to match the different sword types to the four metal murals of the knights on either side of the locked door—it's probably worth grabbing all of the swords already set into the murals before you start doing this. Now, from left to right, you'll want to insert the swords in this order, matching the murals:
Once all blades are in their correct places, the gate will then open and you can progress with the story.
