BONEYARD
Sarduris
I was buffed up beforehand. I step through the portal and arrive at #1 on the map. That includes Kaelyn casting Owl's Wisdom on Valeria, as it will be needed to open a particular dialogue option that will come up when Valeria speaks to Myrkul.
I am greeted by the leader of the Knights of the Undying Dragon, Sarduris. There won't be any hostility from them, at least not yet.
Myrkul
I go on ahead and speak with Myrkul at length, exploring every possible dialogue line. I also get an xp bonus for successfully using my enhanced Wisdom score to get Myrkul to admit that the Spirit Eater curse was a contingency plan to keep his consciousness intact should he ever be slain (which he was by Mystra during the Time of Troubles).
I have three options at the end of the conversation, leave him be, use Eternal Rest on him, or use Devour Spirit on him. Eternal Rest is the good way to end things, and it would earn more influence with Kaelyn. However, I want the Ravenous Incarnation power that comes with using Devour Spirit on him, and for a specific reason. It does, however, result in losing influence with Kaelyn, but that's a triviality since I've already earned the Devotion of the Menagerie feat from her.
The Ravenous Incarnation ability itself is a form that the protagonist can turn into. Its claw attacks will replace any weapons wielded by the protagonist, but they can inflict extra negative energy damage and have a chance of paralyzing their targets. They also have a chance of draining the target of spirit energy on contact. The form itself enjoys damage reduction 15/divine, and immunity to cold, electricity, and mind-affecting spells. The drawback is that using the ability will crank up the protagonist's Craving meter.
Also, the very act of using Devour Spirit on Myrkul maxes out Valeria's Craving meter.
Knights of the Undying Dragon
Now the Knights of the Undying Dragon will charge me from the rear. They can hit for hefty damage. Valeria and Safiya each hit them oncoming with Empowered Firebrand spells. Gann rushes forward to interpose himself between Ammon Jerro and the Knights. He then unleashes an Empowered Firestorm. Kaelyn throws in a Word of Faith for good measure. The battle is soon won handily.
Sarduris leaves behind the Deea Pouch (+4 Strength, +12 Intimidate, -4 Wisdom, -10 Diplomacy). Just having the item in a character's inventory will confer that character with its benefits, but also its drawbacks. I don't bother. I also loot several Brilliant Air Essences and several Brilliant Power Essences.
The portal to the Founder's Sanctum will be at #4, but I don't go there just yet. I want to leave out the portal at #1. There is a specific reason why.
*Evil* Myrkul
I also have Zarathos devour Myrkul's spirit, despite the loss of influence with One of Many, in order to attain the Ravenous Incarnation power. It is a prerequisite to getting the evil ending. Doing so costs me -35 inflence with One of Many, but that is ultimately inconsequential since my acquisition of the Greater Negative Aura feat is permanent. I won't lose it just by falling out of favour with One of Many afterwards.
One thing to keep in mind is that it is also possible to let One of Many devour Myrkul. What will happen is that Myrkul takes over as the one, forcing the protagonist into a one on one fight which can be really tough. Myrkul's One of Many hits often for a lot of damage, has a LOT of hit points, and regenerates rapidly. If your protagonist is powerful enough to win, you can either beat One of Many into submission, or use Devour Spirit on him and obtain One of Many's Essence, which can be used in conjunction with Mold Spirit to add +10 Strength to a belt.
Back to the Slumbering Coven
I don't go into the Founder's Sanctum just yet. My intention is to actually return to the Coveya Kurg'annis. It is now time to realize the long term plan that I put into motion when I first petrified all nine members of the Slumbering Coven by casting Flesh to Stone on them.
Valeria now returns to Mulsantir through the portal that leads back to the Shadow Veil Theater. Ammon Jerro at this point will leave my party temporarily until I return to Thay.
My Craving is maxed out, so I have to be careful. In fact, I'm almost completely depleted of spirit energy by the time I reach the Lakeshore, I have to be willing to use Satiate if push comes to shove.
It happens to be night time conventiently enough, so I take the Shadow Portal leading to the Nightshore.
Once I take the portal, I travel through to the other side of the bridge. I reach the portal that allows me to re-enter the Coveya Kurg'annis. Remember, that portal will remain open so long as I don't loot the dead bodies of Guards Mulv and Turlok.
After that, I issue a 'follow me' command. I also go into my companions' behavior menus and disable their melee attacks. I don't want any of them physically attacking members of the Slumbering Coven.
I take that portal and make my way back to where I had left all nine members of the Slumbering Coven petrified.
Slumbering Coven Essences
The goal is to collect all nine of the Slumbering Coven Essences. First, I disable melee attacks for everybody besides Valeria. The reason is that nobody attacks and kills one of the Hags without my getting a Slumbering Coven Essence out of it.
Now that that's out of the way, the plan is to utilize the Ravenous Incarnation power to obtain the Essences. It's the only possibility for Valeria, as she will be unable to obtain the Devour Soul feat on account of having spared Okku. But using Ravenous Incarnation to obtain the Essences is rather tricky and involved.
Firstly, it's important to describe how the Ravenous Incarnation's attacks work. The form begins with two claw attacks. Each claw attack typically does about 35 to 45 points of physical damage. Sometimes it does as little as 30, or as much as 65, but 35 to 45 is typical. Each claw attack will also always inflict +5 negative energy damage.
Each claw attack also has a chance to drain spirit energy from its target. When this happens, the claw attack will inflict an extra 2-12 negative energy damage on top of the usual 5 points of negative energy damage.
*IMPORTANT* It is critical to remember that it is only when that extra 2-12 negative energy damage, that also recoups spirit energy for the protagonist, and brings the target's hit points to zero that it will result in the obtainment of an essence (e.g. Spirit Essence). If it is the claw attack's physical damage or the usual +5 negative energy damage that brings the target's hit points to 0, then the target creature will die without any chance of triggering the extra 2-12 spirit draining negative energy damage.
So let's go over the two initial claw attacks from the Ravenous Incarnation will do:
Therein lies the tricky part. For each Hag, I need to inflict some damage on it first just to bring it within the right distance. Stated another way, I need to reduce a Hag's hit points just enough in order to maximize the chances of the spirit drain on the second claw attack bringing the Hag's hit points to zero and thus earning the Essence. But since I've petrified all of the Slumbering Coven Hags, I can go about it at leisure.
First, I create a backup save. Next, I'll start off with Valeria softening up the Coven members with an area-effect offensive spell or two. After that, I go to work on each member of the Coven individually. If an individual Coven member still has a lot of hit points, sometimes I use a spell like Harm or Empowered Polar Ray to bring it down a few pegs. If I'm getting close to the ideal range (i.e. 'badly wounded' and about a 1/3 to a 1/4 of hit points left), then I start to peck it down with attacks that inflict minor damage. Such attacks include things like Magic Missiles or Creeping Cold from Gann, or a stab of the Dream Dagger from Safiya. I sometimes play test by transforming into the Ravenous Incarnation form and attacking the wounded Hag. If the Incarnation's claw first couple of claw attacks leave the Hag barely alive, and with more or less no "red" showing up in her health bar, that means I'm pretty much at the optimum point. At that point, the Incarnation's claw attacks stand a fairly good chance of obtaining the Essences I want, so then I reload and move onto the next Hag. If some 'red' still shows up after a pair of attacks from the Incarnation, I reload and peck it down a little more until I more or less get it just right.
I do this process on two or three of the Hags at a time. The idea is that I can then use Ravenous Incarnation, attack them one at a time, and hopefully obtain two or three of the Slumbering Coven Essences before the Ravenous Incarnation wears off. If the Incarnation's attacks score an Essence, I quicksave. If the attacks don't yield an Essence, I reload and try again. Sometimes my estimation is a little off, so for a given Hag I may still need to peck it down a little more.
I repeat the process on all of them until I get all nine Slumbering Coven Essences.
Eyes of the Coven
I've accumulated all nine Slumbering Coven Essences, so now I place five of them in the Enchanter's Satchel. Using Mold Spirit on the Satchel creates a helmet called the Eyes of the Coven (+9 Intelligence, +9 Wisdom, +9 Charisma, True Seeing (9) 1 / day, Premonition (15) 1 / day, Weird (17) 1 / day). It's probably the best helmet in the game, and worth the effort. The spell-like abilities, especially Weird and the extra Premonition, are handy to have. And indeed, Valeria would not normally be able to cast Premonition as a Divination spell, but now she can use it as a backup in case she loses the Premonition from her Shades spell. The bonus to Charisma will help Valeria with her conversational skills. The bonus to Intelligence is obviously the key benefit for Valeria, as Intelligence is crucial to so many of her abilities.
I then place Valeria's rapier in the Satchel, along with the remaining four Essences, and then use Mold Spirit on the Satchel. This adds the following properties to the weapon: +7 enhancement bonus, Darkvision, 5% chance of Sleep DC=22. As long as one enchantment slot remains free, I can sneak all of the enchantments onto the weapon.
Remember Mystra's Blessing that I found in the first Barrow of the expansion (available as Collector's Edition)? It can be used to further enchant any weapon, no matter how many prior enchantments there may be on the weapon, and will add the following properties: +1d6 magic damage, True Seeing, and immunity to illusion spells. Now is the perfect time to use Mystra's Blessing on Valeria's rapier.
The final product is the Blade of the Weave (Adamantine Rapier +7, +5d6 electrical damage, +5d6 acid damage, +1d6 magic damage, True Seeing, Darkvision, immunity to illusion spells, 5% Sleep DC=22). Not bad ...
Satiate and Suppress
A drawback from using Ravenous Incarnation is that it has cranked up her Craving meter right back up to the max. And she doesn't have abilities like Devour Soul or Spirit Gorge to compensate. It becomes a question of how to get her Craving back to zero.
Valeria has a lot of xp well beyond her maximum 30th level. Therefore, the most expedient first step is to simply wait for her spirit energy to drop to less than 10 points and thus reach Stage 4 of her affliction. She can then use Satiate. Satiate restores my spirit energy and drastically reduces my Craving. She's accumulated a lot of xp and cannot advance beyond her 30th level anyway, so using Satiate now is no big deal.
After that, she returns to the Sanctuary in the Ashenwood. Using the Suppress ability in the presence of the multiple spirits allows her to reduce her Craving to zero.
I make my way back to the Boneyard. The portal to the right of the now very dead Myrkul leads to Act III the Founder's Sanctum.