Nice Work
I was particularly impressed with how effective your animation was in this...especially when the project only had one animator. Your use of sound was great, and the visual effects were good. The story telling was also very effective. I especially liked the beginning; how you summarized the heros' slaying of the previous monsters before Diablo. The introduction leading up to the battle was as compelling as the battle itself. You summed up a lot of events in a very clear and dramatic way. My only criticism would be to possibly work a bit on the character design of the heros. I personally like the characters to be a bit more visually distinct but that's a minor suggestion.
You do great work! 'Hope to see more!
-nm