I am not really sure if this is a bug or not, but I thought I should post it here just in case.
I just sent my hero on the 10th adventure. It was a hard adventure. It's my understanding that hero damage should vary from around 5 to 35% damage early in the game, yet this adventure did at least 52. Who knows how much more damage it would have dealt, if I had had more than 52 hp. Furthermore, it is my understanding that if your hero dies on an adventure, you still gain the experience but you do not gain the reward. In this case, I gained no experience.
I assume that my knowledge of game mechanics is lacking and the 52% with no experience is within possible results, but it seems insane enough to warrant me posting here just to double check. I think the most experience I've ever lost on any adventure is 32%, and that was much later in the game, not on the third day of the server.