Missed entry #1.

Quote Originally Posted by The Watcher
The Watcher
Lurker in Darkness, Lurker in Death
Ibrandlin Dracolich Soulbound Weapon Psychic Warrior 12

Legends tell of a gate deep in the bowels of the earth amid the bones of countless dead.

They say that beyond the gate lies the secret to eternal life.

Yet the legends also speak of a guardian. A monstrous sentinel that dwells within that deep darkness and indeed within death itself.

Those who seek to seek to plunder beyond the gates of death intrude into its domain.

Adventurers are not easily dissuaded by legends, however.

And so new corpses join the dead, and the watcher’s domain grows.

Ability Scores
Elite Array: 12 Str, 13 Dex, 8 Con, 10 Int, 15 Wis, 14 Cha
Ibrandlin: 36 Str, 13 Dex, 22 Con, 4 Int, 15 Wis, 12 Cha
Dracolich: 36 Str, 13 Dex, - Con, 4 Int, 15 Wis, 14 Cha
All Stat increases go to Wis.

Build Table
CR Class Base Attack Bonus Fort Save Ref Save Will Save Skills Feats Class Features
5 Ibrandlin (10 Dragon HD) +10 +7 +7 +7 Spot 12, Concentration 7cc 1 HD: Power Attack
3 HD: Area Attack
6 HD: Final Strike
9 HD: Improved Dragon Wings
Fire Subtype, SR 20, Pin, Breath Weapon, Bite, 4 Claws, Gargantuan Size
8 Dracolich +10 +7 +7 +7 Spot 12, Concentration 7 - Undead Type, Extra Damage, Control Undead, Paralyzing Gaze, Paralyzing Touch, DR 5/Bludgeoning, Invulnerability, SR 23, Supernatural Flight, Cha-based Breath Weapon
9 Soulbound Weapon Psychic Warrior 1 +10 +9 +7 +7 Spot 12, Concentration 8 Psychic Warrior 1: Practiced Manifester
Soulbound Weapon ACF: Weapon Focus (Greatclub)
Soulbound Weapon ACF
10 Soulbound Weapon Psychic Warrior 2 +11 +10 +7 +7 Spot 12, Concentration 9 12 HD: Flyby Attack Soulbound Weapon ACF
11 Psychic Warrior 3 +12 +10 +8 +8 Spot 12, Concentration 10 - -
12 Psychic Warrior 4 +13 +11 +8 +8 Spot 12, Concentration 11 - -
13 Psychic Warrior 5 +13 +11 +8 +8 Spot 12, Concentration 12 15 HD: Psionic Meditation
Psychic Warrior 5: Quicken Power
14 Psychic Warrior 6 +14 +12 +9 +9 Spot 12, Concentration 13 - -
15 Psychic Warrior 7 +15 +12 +9 +9 Spot 12, Concentration 14 - -
16 Psychic Warrior 8 +16 +13 +9 +9 Spot 12, Concentration 15 18 HD: Expanded Knowledge (Psionic See Invisibility)
Psychic Warrior 8: Maximize Power
17 Psychic Warrior 9 +16 +13 +10 +10 Spot 12, Concentration 16 - -
18 Psychic Warrior 10 +17 +14 +10 +10 Spot 12, Concentration 17 - -
19 Psychic Warrior 11 +18 +14 +10 +10 Spot 12, Concentration 17, Autohypnosis 1 21 HD: Epic Expanded Knowledge (Schism)
Psychic Warrior 11: Epic Expanded Knowledge (Wall of Ectoplasm)
20 Psychic Warrior 12 +19 +15 +11 +11 Spot 12, Concentration 17, Autohypnosis 2 - -

CR PP* New Powers Known
9 0 Call Weaponry
10 1 Expansion
11 3 Prevenom Weapon
12 5 Dissolving Weapon
13 7 Psionic Lion’s Charge
14 11 Strength of My Enemy
15 15 Escape Detection
16 19 Hustle
17 23 Empathetic Transfer
18 27 Psionic Freedom of Movement
19 35 Schism, Wall of Ectoplasm, Truevenom Weapon
*Does not count bonus PP for a high Wis Score.

CR 5
We start with an Ibrandlin, a Gargantuan dragon out of Monsters of Faerun which has fluff centered around guarding things. We do spice things up by changing up the feat loadout. Area Attack in conjunction with Gargantuan size gives an extra attack option (albeit one that will be more important later). Per a poorly written rule in Races of the Dragon and Dragon Magic, dragons automatically qualify for anything requiring the dragonblood subtype. Automatically means automatically, so we pick up Improved Dragon Wings without bothering with the regular version for some mediocre flight. Finally, Final Strike offers a last threat between the party and their objective should they defeat the Watcher, though again, it’ll get more of a chance to shine later.

CR 10
It transpires that the “secret to immortal life” that lies beyond the Watcher’s gate is really a Dracolich Phylactery. Final Strike will destroy his original body when he dies from consuming Dracolich Brew, so he has to do as the Kobold Dracoliches do and acquire some other corpses to possess. He’ll want them anyway, as Dracolich Invulnerability allows the Watcher to possess any corpse of a Medium or larger dragon or reptilian creature within 90 ft of his phylactery. That means that when a given body is destroyed (triggering Final Strike), he’ll just hop into another one and continue the fight. And what can he do while fighting? Well, first off, Dracolichdom confers Cold Immunity, covering the weakness of the Fire Subtype (though that’s a bit of a moot point what with dying being such a minor inconvenience). Next, despite no longer qualifying for Improved Dragon Wings, he can still fly as becoming a Dracolich explicitly converts a previous Extraordinary flight speed to a Supernatural one. Finally, and most importantly, he gets the super cool (pun intended) Dracolich version of Paralyzing Touch, which applies on “any physical attack,” which includes not just his full attack routine, but also Area Attack, allowing him to force saves against paralysis to multiple foes at once. From there, we go into Psychic Warrior. A Proto-Dracolich (one that has just possessed a corpse) can’t speak or cast spells, but the standard transparency rules aren’t enough for that to inhibit Psionics. Practiced Manifester allows for a bit more utility with powers, though they’ll become more impressive as we go on. CR 10 also brings Flyby Attack, which can be used with an Area Attack, as it only takes a standard action.

CR 15
Now that the Watcher has a few more levels of PsyWar, he can do some more interesting things with manifesting. Soulbound Weapon allows him to use Call Weaponry to pull out a magic Greatclub which can be augmented for whatever non-flat enhancements will still work when it’s repurposed as an improvised weapon to make Area Attacks (and which can be recalled should he lose it when a body is destroyed). Expansion can bring the Watcher up to Collossal size, even when in the Proto-dracolich state in a corpse that’s merely Huge. Prevenom Weapon and Dissolving Weapon get a lot more bang for your buck on an Area Attack, making the mass paralysis attacks even more devastating.

CR 20
Now we’re cooking. With Practiced Manifester, the Watcher’s ML is now high enough to augment his Soulbound Weapon up to a +4 equivalent bonus, allowing for enhancements like the +3 Force (for dealing with Incorporeal and Ethereal foes) or +4 Brilliant Energy (allowing for tricks like possessing a corpse buried underground or hidden behind the gate and making Area Attacks through solid obstacles – be sure to cultivate moss or something on the claws of his various bodies so that there’s living matter the brilliant energy won’t ignore). Epic Feats are now available, which allow the relatively option of picking up some 4th level powers from outside the PsyWar list via Epic Expanded Knowledge. Wall of Ectoplasm is the more straightforward, allowing for further protection of the Watcher’s gate, especially against ethereal threats. Schism is where things get especially hilarious though. Note that I’m assuming that Immunity to Mind Affecting can be voluntarily lowered, but I think that’s a reasonable assumption. If you disagree, then some other 4th level power from some list or other can go there instead, but Schism is way more fun. First off, the Schismed mind can handle all the usual things you might want it to do, such as manifesting powers while the regular mind directs the body to fight, but let’s go a step further and consider what happens when the Schismed mind is sent back to his phylactery. I had at first thought that the two minds might be able to possess corpses separately and thought about having a gate made out of a corpse which the partitioned mind would possess and then secure through powers like Immovability, but ultimately concluded that was a stretch of what the power actually says, and decided the parts of the mind would stick together when possessing new corpses. That does however free up the partitioned mind to handle corpse possessing duties, meaning the Watcher now effectively doesn’t have to stop fighting at all. If his body is destroyed, it explodes in the face of the attacker, and the Watcher is inside a new one making more Area Attacks by the following round. Regular PsyWar powers known also contribute with Psionic Freedom of Movement making it more difficult to incapacitate the Watcher in a way that won’t cause him to just blow up and reappear in another corpse, and Truevenom Weapon augmenting Area Attacks similarly to the earlier weapon powers. The Watcher also has a few metapsionic feats to play around with and Psionic Meditation for either his regular or partitioned mind to restore Psionic Focus mid-combat.

Using the Watcher
Post Dracolichdom, the Watcher becomes very difficult for the party to destroy. Should they want to pass the gate, they will either have to do so with the Watcher attacking them, incapacitate the Watcher through some mechanism besides HP damage, or win through sheer attrition by exhausting his supply of corpses and/or PP. These should all be difficult, but not impossible if the party is clever and determined. While they won’t find the real secret to immortality hidden behind the Watcher’s gate, the sense of accomplishment and the treasure trove that is there ought to be some consolation.

Complete Psionic: Escape Detection, Psionic See Invisibility
Draconomicon: Dracolich
Monsters of Faerun: Ibrandlin
Races of the Dragon: Dragon auto-qualification rules, Improved Dragon Wings
Savage Species: Area Attack, Final Strike
The Mind’s Eye Expanded Classes: Part One: Soulbound Weapon ACF
Everything else should be in the SRD.