My brother and I did the quest to kill prince nanu and the rest of the quest but it made me have to start all over! Now I can't get the braziers lighted to kill him and I can't get in the doors.
If you go out of the throne room of fire the progress you made does not save i had that same problem.
Blaze Ghost Staff lvl, 26 Fire Wizard
I too had this problem and when I asked around, the conclusion was that it's a "wonder" of the "Instanced Levels". Meaning that your journeys are not saved. Unfortunately, you MUST complete the levels completely without being "Defeated".
Trust me, I got really annoyed with that! I share my account with five other people and one of them really wanted to help me get past Prince Nirini! Basically, you have to defeat him, then without fleeing or dying, defeat the next guy too, but I forget his name. After you did BOTH of those things together, you can continue on without having to start over. Also, it is helpful if you have someone battle with you.