What’s lucky about that? You miss opportunities to get beneficial treasures.
What party did you use and how does it fail?
Although one could have probably spent time better, I’ve actually done it on Heroic now… without losing anybody… with the following party: Velen, Cornelius, Anduin, Varian, Xyrella, Bru’kan. For the boss, you should only need Bru’kan, Velen and Anduin. The strategy is as described above. I had a couple of useful treasures (Strength of Wrynn 5 and Blessing of the Moon’s 5 respectively), but nothing game-changing (although having some spellpower has helped to get rid of a water elemental with Anduin at some point), and I’ve intentionally avoided using something like Val’anyr. Velen took a bit of beating, and I couldn’t resist throwing in a bit of chain lightning at some point, but otherwise it didn’t seem that impossible.
Mind you, for the event one doesn’t even have to do it on heroic.
PS Wait, the event isn’t even over yet, is it? Meaning you can still do it.
PPS Alright, after one ‘failed’ attempt, where I’ve actually been bailed out by the ‘Resurrection’ treasure, but played sloppily, I’ve done it again, this time picking ‘useless’ treasures (i.e. passive ones that don’t contribute to the fight or active ones I would not use, despite their quality, in order to simulate having no treasure) purposefully, quite easily, so this is probably as representative and reproducible as it goes. Here’s the key: Bru’kan keeps slowing the left, blue enemy for as long as needed (namely, while Ravak is still up), Velen and Anduin work on the rightmost red guy with their first skills initially, and, due to the water elemental being summoned on turn 2 and the way speed ties work in PvE, use the combo (Velen’s Blessing + Holy Nova) on turn 3, clearing it up and avoiding problems with being frozen.
Although initially I’ve done it with Uther in order to test him while at it (I don’t recommend Uther now, by the way, just play it safely and use Bru’kan instead, who’s also more easily available), played it somewhat sloppily (misclicked at an important moment), have been bailed out by ‘Resurrection’, thus completing the actual task, and haven’t bothered with it much, now I’ve found it to be a curious little puzzle. I repeat: it’s easiy doable even on the heroic difficulty instead of normal, without any treasures or any particular luck, I’ve even described in detail how (and the party I’ve suggested is, in my opinion, one of the best for climbing in Alterac, so you should be fine there as well), and I don’t know how badly one has to play in order to fail it. If you haven’t got Velen and Anduin, well, I suppose you could look into more budget options and do it on normal difficulty instead…