Take a look at the RtL encounters. More precisely, check the attack types of the leaders and their minions (if any).
Count how many are (almost) completely made up of monsters that use melee attacks. That's right: 11-13 out of 29.

Then bring to mind the horror that is Zyla.
Ghost. Lovely isn't it. Immune to adjacent melee.

"That's ok, I have melee-based monsters with Reach! Hah! That'll teach her".
And that's when Zyla ends each of her turns in a tree space. Shadowcloak + Ghost.

Combine that with the other 3 heroes in her party fleeing the map (possibly after killing the only non-melee monster in the bunch), while Zyla stays behind to mop up.

Other than wanting to know what genius conceived that obnoxious gnat of a hero, I don't really have a question. Guess I was just looking for a place to vent frustration over a situation where it becomes impossible to damage a hero.

No really, what is supposed to happen? Concede 1/3 of the encounters upon drawing the card?

Yeah, when she's properly used she can be really nasty. The funny thing is that when we played "A Small Problem" (the obscene kobold quest in WoD), one of the players had her as a hero, and he absolutely hated her because despite her abilities, I was still able to take her down repeatedly with traps, skeletons, and dark priests. She definitely forces the OL to adapt his tactics. The sucky part of that is that those tactics are often not the greatest way to take on the OTHER heroes.

Or impossible given some of the encounters the OL gets in RTL and the fact that the OL gets no cards.

I really don't think that Ghost is a good idea, either for monsters or heroes.

In Enduring Evil, I suggested that Zyla's Ghost ability be replaced with Disruption , which causes any attack made by an adjacent enemy to be automatically "dodged" (even if it doesn't target the disrupting figure). Still makes her resistant to melee, because they can't avoid the effect, but she's far from immune.

What I don't understand is why she's only 1 point. I'm not too concerned about Ghost*, but it's definitely a strong enough power when coupled with Fly and 5 fatigue that she should be worth at least as much as the other 8 health characters with 1/1/1 for starting skills and traits.

* yet, I haven't seen it in play, and it definitely sounds scarier in RtL than Vanilla.

Probably because she has very few hit points and horrible trait dice.

OK, admittedly, conquest value does seem to be influenced by how generically powerful a hero is in several cases, but it shouldn't be (at least not significantly). The split traits and skills should be there to balance the amazing ability, not to compensate for an undeservedly low conquest value.

Zyla is presumably worth 1 conquest because she is the only published hero with 8 health and 0 base armor (every other hero has at least 12/0 or 8/1).

Strategically speaking, that's probably not a large enough reduction in defenses compared to other 2-conquest heroes to warrant the drop, especially when she also has a powerful defensive ability, but it's at least an understandable decision.

Well, she is broken I'd play her as Dodging, as suggested, or simply her.

I do agree about Ghost being a silly ability. It's too swingy- either does nothing or cripples the other player. Shadowcloak is a good, interesting, well-designed ability. Ghost is not.

To the original post, do bear in mind that Ghost+Shadowcloak does not equal Invulnerable: you can still be targetted by adjacent Ranged and Magic attacks.