Location
The Auriza Side Tomb is located within the Capital Outskirts on the Altus Plateau, just before you enter Leyndell itself. Head northeast through the Outskirts until you're on the eastbound road to Leyndell's entrance, where a Draconic Tree Sentinel waits. If you check the cliffs along Leyndell's walls you'll find a shallow moat at the bottom.
Follow the moat east and it'll take you under a bridge and over to Auriza Hero's Grave, a large, obvious building protected by a bear. Take a left at the entrance and you'll run into an enormous Lesser Runebear. Beyond its hiding spot, carved into the rocky walls ahead, is the entrance to the Auriza Side Tomb.
Auriza Side Tomb
Trigger the Site of Grace and head inside, where you'll find the locked door leading to the boss of the tomb. The first thing you should note is that you cannot summon multiplayer help into the Auriza Side Tomb. Ashes can still help you with the boss, but other players are a no-no. You also can't be summoned while inside the tomb.
Take a right and down the stairs from the boss door. In the next chamber you'll discover a collection of small Living Jars that will amble up and attack you. They're not terribly threatening, though some of these Jars will explode once defeated. You have about two seconds to roll away, so get clear once the Jar begins to glow or you'll take damage. There's a Grave Glovewort [6] in this room.
Go down the next set of stairs to the north. You'll find a room with a chest. If you open the chest and allow the mist that seeps out to catch you you'll be teleported elsewhere in the dungeon. This will happen several times, and if you don't have a great sense of direction it can be easy to get lost. Allow yourself to be teleported.
You'll emerge near a two-story hallway. Go down the stairs at the entrance of the hallway and look beneath the landing where you started to find an imp that's guarding a Grave Glovewort [6]. Two more imps wait in the archways to the west. Take them out, then go left to find a Grave Glovewort [5] beside a doorway.
Go through the doorway. You'll wind up in a water-logged room, and an imp on an archway above you will toss Lightning Pots into the water. The effect of the pots spreads out a bit more in water, so watch out. There's a sizable jail cell in this room, but you can't open the door, so take a right and keep going.
Next up is a chapel. There's an imp on the ground waiting to ambush you when you go through the door, and a second imp is on the upper level to your right, eager to hurl Magic Pots. Take them both out. There's a chest in this room that will teleport you elsewhere, guarded by a third imp, and if you check the wall niche on your left you'll find a fake wall hiding another room with a Grave Glovewort [5] and a second chest. This hidden room contains two Living Jars that will chase you around and try to explode.
Start by opening the obvious chest inside the chapel. It'll teleport you into the prison cell you saw earlier, and two full-sized Living Jars will rise up and attack. You can use the columns in this room to keep them from overwhelming you as you chip away at their health bars. The cell contains the Perfumer's Cookbook [3] and two Cracked Pots. The chest in this room will zip you back to the chapel.
Head back to the hidden room off to the side of the chapel and open the chest. It'll teleport you to the upper walkway of the chapel. There's an Imp nearby, and another down a hallway straight ahead. Snag the Golden Rune [7] on your left before you proceed. If you go down the hallway and follow the path you'll fight your way to a dead end. Confused?
There's a trick at play here: You're actually in an (almost) exact duplicate of the area you were already in. The enemies are roughly the same, but there are new items to be found, and the teleporters lead to different places. It's very easy to get lost until you realize that you're in a different section of the dungeon than before.
Hop to the lower floor. Beneath the stairs that seem to lead back to the entrance you'll find a Ghost Glovewort [6], as well as an imp. If you try to head back to the entrance you'll find a dead-end room containing a large Living Jar and a smaller, exploding one. Back out of the room and take them down at a range. You'll find a Ritual Pot and two Root Resins once the room is cleared.
Head back to the chapel and use the chest on the altar to jump into the alternate jail cell. Two more small Living Jars await, along with a Ghost Glovewort [6] and two Cracked Pots. This cell has a ladder in it, and climbing it will bring you to a Grave Glovewort [6], as well as the switch to open the door to the boss. Jump down from this perch and go up the nearby stairs. The chest you'll find will take you back to the entrance, where you can tangle with the boss.
Grave Warden Duelist
If you've already explored Leyndell - or one or two other optional areas in Elden Ring - then you've probably faced a Grave Warden Duelist before. These hulking bruisers are faster than they look, and this particular one has chained weapons that allow him to hit hard at a bit of a range. He also has a group of Living Jars running around that will get in your way as you're trying to avoid the Duelist's attacks. Some tips:
- This probably goes without saying, but take out the Living Jars first. They will only require a few hits each. Wiping them out at a range is best, so you can keep an eye on the Grave Warden Duelist.
- Don't block the Duelist's attacks too often. His hits do a lot of poise damage, and will stun you after a few hits. Rolling under his attacks will give better results.
- Use the pillars in the room to keep the Duelist away from you when he's winding up an attack. Once he stops you can move in and get a few hits of your own.
- Call in help. Spirit Ashes will make this fight significantly easier, allowing you to take out the Living Jars before needing to face off against the Duelist.
You'll receive 15,000 Runes and the Soldjars of Fortune Ashes for defeating the Grave Warden Duelist and his Living Jar buddies. You can now leave the ever-confusing Auriza Side Tomb behind.