I was playing last Thursday against Fyreslayers with Alarielle on the board. She's clearly overcosted same as most Sylvaneth units. She was useful but certainly it would have been a better deal to take f.e. Drycha and Durthu in her place. She helped me snipe Fyreslayers small heroes although I had really bad rolls (turn 3. throne of torns: double 1, metamorphosis: 1 and 3, mystic shield: double 1. my opponent laughed). One good thing was that because of heroic action and her healing spell my opponent wasn't targeting her at all afraid that she will heal up before he can kill her.