Actually a number of things reset the dungeon immediately- leaving through the entrance, porting to your house, logging off are a few examples. Plus, you need to get something from the oni that you didn't know you needed. If you go to the store and pick up milk, having to cross crocodile infested rivers, jumping over poisonous scorpions, and leaping over deep pits to get there (as most of us do), then return home to realize you need bread now, you've got to go back out to the store facing the same perils. ...well, ok, that's 'Pitfall', but my point is still the same. Though i could be totally wrong. -eli and crew
Actually look at it on the bright side, we all have to repeat a number of quests to get things ( obsidian chests for example, oh the boredom of the labrynith. :) However all is not lost! consider the chances of getting that rare item drop! Well worth the the replay!
wow didnt know how easily life and storm had it for dryad/triton (i am thinking you are talking about your level 38 quest correct me if i am wrong) we had to complete the plague oni, but the way it was set up, we had to defeat the first boss to get through the gate, and then the gate to the temple just dissapeared, allowing access to the oni. i know this because my life went through it one day with a storm, and then the next day, the storm had to beat it for his quest lol