Take the path upwards and turn right at the gate. Go higher and go underneath a plank. You'll be in a dead spot and enemies will appear. Fight, but mind you there's little room to maneuver. Try to practices counters, dodges and blocks - this will come in handy later on.
After the fight, go upwards and examine another Lorestone. Then go further on, underneath a broken pillar and jump down. Stick to the path the whole time to reach another Valravn's gate. This time, however, there are more symbols, and you will need to reduce their number to be able to get across.
Begin by going through the door that is right of the gate. Then go left, take the stone stairs (opposite of the main gate) and take the wooden bridge. Then go around the broken tower and enter it.
Unlock the door and enter the narrow passage, where you will find a Lorestone. You have to retrace to the first portal that alters reality and enter it. Lower the bridge next to the tower to be able to get across and then enter the gate. After you do that, enter the tower and go up. Go through the portal and half of the symbols will disappear.
Go back to the bank where the main gate is and enter the portal again. This time go left, jump up and use the plank to get to the other side. Find another bridge, lower it and get across. Enter the Valravn's gate again and use the lowered bridge to get back near the tower.
Go up, take the portal and another set of symbols will disappear. Now you need to get to the main gate, use the protagonist's sharp eyes and unlock further passage. Use the door to enter your enemy's headquarters.