Very cool for any Celtic flavored game and cool for any game to be honest.
The warp-spasm of Cú Chulainn is something that has been in the stories of the Ulster cycle, but never really implemented well in a game. This is a pretty good way to do it.
If you are running a Celtic game, then this is a good product to have. Great price as well.
[5 of 5 Stars!]