I've had a flick through it and I came to the conclusion that you could come up with some really cheesy lists using it.
Yea the 13th spell is completely broken, I think its a 25 to cast, I had the 3 core. Before the game Mike Butcher told me about the 13 spell so I deployed two of my 3 heralds together and kept them all out of the core units. Had 1 unit of bloodletters with full command, he immediately targeted that unit in the 1st turn and eliminated them rolling five dies getting double 6s. Turn three he does it again on my unit of 10 bl's this time rolling a 26. The Heralds become a target for the death bomb of two doomwheels in a pincer move. Then all of the shooting of course is targeted at my BT, and then all of the crap the screaming bell does. By turn 6 I had nothing left. I definitely thought this army was broken as it did everything well, it reminded me of 40k powergaming. I think his comp score should have been a 1 or 2, but instead it was higher than mine, I chalk that up to Khorniphobia. Mine is broken just in one phase of the game: combat, you have good magic or shooting, its very beatable.
As to the trophies, I was thrilled to win this, almost won the shield also. He also made a huge choppa, shield, and scaled down bolt thrower...here's a link to the trophies:
http://www.wwhfb.com/forum/viewtopic.php?f=7&t=922