Zante

I registered just to post this. The same thing happened to me once I got to the catacombs. My obsidian lamp ended up allowing one shadow to exist post combat, after the others were unsummoned. It's worth mentioning that I'm also going for the solo achievement. I don't know if this, combined with the catacombs is what's causing problems.

I'd love to see some battles which are almost impossible to win. Something which isn't friendly to the player but makes a statement in the gaming world. It could be a deity, a dragon or otherwise. There's nothing more soul crushing than realizing you have become the most powerful individual in the realm and that no other challenges exist. Dynamic multiplayer content: Randomly generated multiplayer quest objectives. You won't know what they are until you begin the quest and there is no way of knowing where in the gaming world they will send you. They might involve retrieving an artifact or seeking after a bounty. Better yet, have a mission board from where players can decide what they ought to pursue - minimizing the likelyhood of people restarting the session if they don't get what they want in terms of an objective.