Mystery Girl in Palace of the Dead

[Nestama]

Want her back story, here it is: She failed to heal her tank, who was also to dumb to stick near the party. After he died she went crazy and killed most of the rest of her party trying to necro the tank back. Along comes the god slayer to put her down. The end.

Not quite. Edda's story is told throughout Tam-Tara HM (the notes). She was in denial and decided to go adventuring with Avere's head (her home town was too small for her liking now that she saw the world for herself)... which did not help her sanity (one note implied she shared a kiss with Avere. Pretty gross). She eventually learned how to put souls into corpses (sometime after her visit to Thanalan and possibly Coerthas) and after raising Liavinne from the dead (who was killed in the Waking Sands by the Garleans), she sent out the wedding invitations.

She probably learned how to raise the dead from some Alchemist or something.

Ever since, she haunts the playground in Gridania (and possibly other places, but the playground is the only notable area people know of).

[Enkidoh]

Not quite. Edda's story is told throughout Tam-Tara HM (the notes). She was in denial and decided to go adventuring with Avere's head (her home town was too small for her liking now that she saw the world for herself)... which did not help her sanity (one note implied she shared a kiss with Avere. Pretty gross). She eventually learned how to put souls into corpses (sometime after her visit to Thanalan and possibly Coerthas) and after raising Liavinne from the dead (who was killed in the Waking Sands by the Garleans), she sent out the wedding invitations.

She probably learned how to raise the dead from some Alchemist or something.

Ever since, she haunts the playground in Gridania (and possibly other places, but the playground is the only notable area people know of).

Except that is not entirely correct - as it was stated time and again throughout the game that to truly revive the dead is almost impossible (because to revive a soul would theoretically require it to be pulled from the Lifestream, by which time it would have simply diffused into it,

remember just how much trouble it was to get Y'shtola back from the Lifestream and she technically wasn't even dead!)

. No, so-called 'necromancy' isn't actually reviving the dead at all, instead it just ends up summoning a voidsent which possesses the corpse, and this is what happened with Edda -

she didn't revive Avare at all, but ended up summoning a voidsent into Avare's head, turning him into a kind of ahriman. This was also what happened in Tam Tara NM with Galvanth and the Lambs of Dalamud, that wasn't the real King Galvanth at all, but a mindflayer wearing his name(and presumably what's left of his body).

Despite what Edda might have believed in her grief-stricken insanity, she had not 'resurrected' Avare's soul at all - he had long returned to the Lifestream, the River of Aether if you will, but instead summoned a demon that wore his head as a meatsuit. It also explains all the 'rejected bodies' found in Tam Tara HM, these were also voidsent she summoned. In the end she wanted to use the player's own body for 'Avare', showing she had well and truly gone beyond all reason and sanity.

I still believe Edda's fall into the dark arts was at the very least nudged on by an Ascian, as it just seemed such a flip from when we last saw her, promising to return to her hometown and concentrate on being a better healer (her lack of aptitude in Conjury is after all what cost Avare his life in the first place), to summoning voidsent and going completely insane (and such a thing is well and truly within the Ascians MO). But then, grief can really make you lose all sense of reality if have no one else to turn to or help you.

But I digress....

[kuma_aus]

I still believe Edda's fall into the dark arts was at the very least nudged on by an Ascian, as it just seemed such a flip from when we last saw her, promising to return to her hometown and concentrate on being a better healer (her lack of aptitude in Conjury is after all what cost Avare his life in the first place), to summoning voidsent and going completely insane (and such a thing is well and truly within the Ascians MO). But then, grief can really make you lose all sense of reality if have no one else to turn to or help you.

She was carrying Avare's dead head around. If that doesn't scream "Crazy Lady", I don't know what else does. It would feel like a massive cop out to me if in the end it turns into "Ascians are behind everything again!" instead of a unique character that lost a bit of sanity when the love of her life died with some of the reasons why on her own hands.

[Nestama]

snip

I mostly made the assumption on Alchemy because of a certain Beastman quest (where an ALC was going to raise a zombified army of Beastmen, if I recall correctly).

Then again, Necromancy is definitely a thing in the game (so Edda probably went into the restricted section of the THM library)... I couldn't remember correctly, but after looking it up, child Minfillia in 1.0 allied herself with a necromancer (thought it was an alchemist, but was wrong) to try and bring her dad back to life.