I disagree...
Even if Nualia had used her ability for another two rounds, she wouldn't TPK us. She would probably drop the Paladin, but all the other characters finish the combat with plenty hit points (even the other fighter at front line). The paladin was near dead, but the party, as a whole was far from defeat.
It has the same problem that all the area attacks, you need to "forget" the character laying in negative hit points, or you risk killing them.
Note that we also made some tactical mistakes, I didn't realised that "remove fear" was a range power until later in the combat. If I did, I could cast it on the bard, and she would be able to join the battle. Not only would this help to defeat Nualia, but also make the combat more enjoyable to her (the bard not Nualia ;).
I really believe that you could have pressed us a little bit more without killing the party.
But yes, I need to take that feat ASAP, it's a must-have for a cleric.
BTW, I was Averin the cleric, who probably needs to check the use of conditionals sentences in English.