Forget my customary opening to most of my reviews... This will suffice.
This utility is a excellent idea. It is a great way to give the look of ashes and rocks coming out from a volcano. Only minor complaints made this utility drop down to a 4.5:
-The deer could have been made stronger, but even so, the volcano effect only lasts so long.
-The trebuchets are completely visible to the player. Objects such as mountains could have been placed in the way to hide them.
Despite these very minor problems, the utility is great. The trick is explained, an excellent looking map was provided, and it's a useful trick. Worth the download.