Summary: Get a Qualis gem and trade it for the location of Al-Aziz.You get runic weapons by trading in Qualis gems in for them at the mines of Al Aziz. For the definitive word on Qualis gems you can check out
this thread. For the definitive word on Al Aziz you can read
this one. What you need to know is summarized here, however. Before I go into details know that you'll need three Qualis gems in total to get access to the best weapons, and collecting that many is a difficult task.
Al Aziz is represented by a mine icon on your map like the salt mines from the old old versions of Mount and Blade. It is in a different location each time you play the game, and when you start the game it will be invisible to you. Brother Randalf is a traveler that can be found randomly in taverns and goes from city to city in Pendor. When you find him you will have a dialog option to trade him a Qualis gem for the location of the mines. If you have a gem to give him he will "mark" the mines on your map, meaning that they will now appear and you will now be able to enter them like any other town or castle. They are typically located in the more remote, unpopulated regions of the map, so look there first. If you have trouble locating Brother Randalf remember to check upstairs in all of the taverns you visit (only a certain number of NPCs fit in the downstairs area of a given tavern) or just wait an in-game week and try again -- not all NPCs are always present in the taverns, though most usually are.
Qualis gems are very hard to obtain. To get them you need to capture unique heroes. These heroes lead the
unaligned super armies that spawn in Pendor (after day 15 or so), typically numbering 600 or more, and always have percentages after their names like heroes have. For example, if you find "The Roc Boyz Legion" running around, a large army with apparently no affiliation to any of Pendor's minor states, and the first person in the Legion's army list is something like "Jay-Z [100%]" you have a possible source for a Qualis gem. Not all large armies have leaders, though, so if you want a gem be sure to pick an army that does -- the 100% is key to look for. Anyway, you will have to defeat the army and you will have to capture the leader of the army. You don't have to use a blunt weapon, the army leaders act like Pendor's unkillable lords and are always knocked unconscious when struck down in battle, but they also always try to escape from capture. Capturing them is purely based on luck, and you have something like a 10 to 20% chance of capturing any given lord at the end of a battle (I'm unsure of the exact number), so you may defeat the army and not get what you were after. If you get the option to capture the lord do so. After the battle open your Party screen, click on the lord in your prisoners list and talk to him, and in the dialog options you will have a chance to set him free in exchange for the gem (or some other things of much lesser value).
Be sure to have an empty space in your inventory before talking to the army leader or your precious gem will get lost! These leaders will respawn with a new army eventually, so so long as you can still beat them you'll have another shot at a gem.
There is also a single Qualis gem in a chest in Rane that's lying in an alley in a pile of hay. (There is a second secret chest in the game in another town but it contains no gem.) Be wary of spending it on access to Al Aziz, though. You need those gems to found
orders of knighthood, and you'll probably need those top quality knighthood soldiers to kill the armies that hold the other two gems you need. So I'd recommend saving your first Qualis gem for founding an order.
