Irisha- 
Personality: Yes, she's more than a little on the psychoticly sadistic side that hides behind the mask of an overly flirty mother figure. She enjoys hurting things and killing things in...quite the messy fashion. That's just how she gets her rocks off. However, she also likes to help people. She has the capacity to be an insane bloodthirsty monster, and a caring mother figure. That's why Tyzitla made her the High Priestess. He sees her as...sort of a reflection of his own personality (Speaking of which, I feel I might need to clarify Tyzitla's own personality a bit I'll do that at the end of this post)

Flesh Mending: Perhaps I fudged the explanation a bit here, my bad. Shadows forcibly [i]mend[/i] wounds. As in, like stitches. Like small little threads of shadow bind the wounds together to prevent whatever damage from becoming worse and hold them together so the person can still function and fight if needed, hence why there are still large, sometimes gruesome scars left over from the process, and why I called it 'Flesh Mending' rather than 'Healing' or something. It's like...putting a splint on a broken leg until you can get a cast or something. The shadow stitches hold the wounds together. It can be a painful process for someone who is unprepared. In a fight, realistically speaking it can't really hold out against actual healing magic and such, but it can give the wounded a second wind and keep them fighting a bit. Is that acceptable? 

Fortification: Hrm. I'm a bit unsure on how to explain this. Think of it as sort of like...a thin layer of shadows coating the body and absorbing a bit of the impact from the incoming weapons and such. That's the best I can do as far as explaining it goes. If it still doesn't sit well, I'll just remove it. Not a big deal~

Zyla: Should have probably said something about this earlier, dude. Gods are notorious for having a lot of children. I mean come on, all of Zeus's problems were mostly because he couldn't keep it in his pants xP

On a more serious note, She's not going to be doing much to start with, at least for now. Later down the road I can see her causing some trouble, (either at Tyzitlas command, or her own boredom) if that is acceptable. If not, I'll just have her as like a side character that takes care of the Citadel. (since they did make this pact, I'm going to assume he did it behind their backs either on accident, or on purpose to have her serve some use later down the road.)

Now, explaining Tyzitla a bit. He appears passive by nature, but has a tendency to protect and help those with more deviant personalities simply because he himself, is a bit on the...psychotic side. Everything for the sake of progress and such, especially with his experiments with shadow magic. Human sacrifice? Been there and done that. Mass murder? Old school, but has it's uses. He regularly asks for volunteers from his populace to help with his research. 

The people of the Vale have much the same nature - helpful and friendly on the outside towards outsiders, but most have a much darker personality beneath that friendly exterior. Sort of like the whole 'the prettier it is, the darker nature it has' type thing.

Lets see....did I get everything?