Blades of Iron is a quest in Tyranny.
Graven Ashe has sent you to Lethian's Crossing ensure the Forge-Bound are protected and can continue making weapons for the Disfavored.
- Head to Lethian's Crossing to meet Zdenya, Master of the Forge. If it's under Bronze Brotherhood control cut through the Ironhaul Trail while wiping out all Bronzemen. This will need to be done to whatever garrison's present if you turned against them at Vendrien's Well. Once the garrison is gone, you can interact with the city as normal.
- Zdenya can be found in the Forge-Bound foundry, known simply as the Forge. It's located east of the river on the first tier of the Moonrise District, just above the ground floor.
- Zdenya will ask you to join her on the third tier of Lethian's Crossing where she will place the Magebane Helm before she will discuss the future of the Forge-Bound.
- Once the placement is done, Eldian will ask you to confirm that the Magebane Helm actually works by entering the Oldwalls at Lethian's Crossing and watching for loosed Bane. You will receive a keystone to enter (note that with Lore 55, you can point out that Kyros' law forbids actually entering the Oldwalls, but that you'll do it for the Crossing →).
- Enter the Oldwalls using the keystone. See Lethian's Crossing Oldwalls - Antechamber for area details. For now, approach the area in front of your party. Something goes wrong and you're attacked by Bane. Return outside to Zdenya.
- Of course, nothing's as simple as that. Iron and Blood begins and your goal is to fight through the Bronzemen. The quest completes as soon as you give chase to Raetommon.