Keep grinding... the boss.

You think back to when you first Hexed your boss. That alone was almost enough to get you to level 5. So repeating that process should multiply your XP income significantly. Obviously it's more dangerous too... First of all you're not even sure that the boss room can be reached without angering The Keeper, and even if you could, actually replicating what you did would take a lot of luck and care. You decide to at least give it a try though. The method you've used until now is far too slow and your patience is running out. It's time to up the risk/reward factor.

You wander around the dungeon section for a while, glad to find a fortunate lack of intruding heroes. You do meet some more monsters that ignore you for the most part. You feel oddly alienated here. Everyone's a stranger that probably already have some degree of relationship with one another, and you're the new kid. You've finally become a full-on nerd, not only in build and behavior but also social standing. You don't intend for that to last though... You're gonna become powerful and awesome one day. One day soon, hopefully.

Eventually you find a part of the dungeon you faintly recognize. It's the part you ran through. From there you quickly find your way to the boss door, standing before it hesitantly. Still no Keeper, so presumably you're allowed to be here. In fact there are some monsters guarding the door, so yes, you are obviously allowed here. Now you just need to await some heroes...