Harassing the players : Dungeon boss

[Iorthol]

Starting with a little background.

The Game : Normal D&D island based game, the catch, no spellcasting (Though there's still abilities/magic)
The dungeon : The players ran their ship into an island and need repairs, they find an ex-pirate cave, with a sunken pirate ship. The ship, upon sinking, crashed through the doors of an ancient crypt. (Or perhaps the ship was pulled down to the crypt) In the ship they've been fighting dominated pirates full of necrotic cysts (from Libris Mortis) and some scattered undead, and some horrific pods I created that were inspired by the Skulking Cyst. Upon reaching the bottom rear of the ship, they found a hole leading further down.
Below is a crypt housing ancient royalty of a nearby kingdom.

Now, what I'm looking for is suggestions to help me design the encounters in this crypt. Currently it's got an entry room, with a flight of stairs spiraling up into the shaft going up into the cave. There's 1 king/queen room, 2 prince(ss)/cousins rooms, and 3 chambers for important members of the court.

What I'm looking for in suggestions : Ideas for the main boss/ the root of the problem. Something has to be animating dead royalty, infecting the pirates with cysts and squishy (Halo) flood-like undead, and they need a reason to have been down there, and to have stayed down there.
Also looking for suggestions on types of undead to use for the encounters in the crypt (they're done in the pirate ship).
Currently I'm itching to use spell-stiched undead, but I'm welcome to other ideas, as well as suggestions for the base undead to use.

To help you anchor some ideas on the main badguy, the main treasure in the dungeon is going to be some kind of spirit/artifact/source-of-power/ancient king(or)queen/THING that will grant the characters special powers.
The special powers are either gaining 2 levels, gaining 1 level and a 1st level spell to have at-will (Or limited, depending on the spell), or to gain no levels but gain 3 spell levels worth of spells to play with.

Currently the party is level 6, with 9 members of the party (Not including NPCs)

[Iorthol]

Also, I need this help by Tuesday the 17th

[JaronK]

There's a PrC in Libris Mortis for undead that's based entirely around protecting a tomb or crypt. Seems relevant to your interests. Perhaps a Necropolitan Tomb Warden that's been Spell Stitched, and has thus gained the various Mother Cyst spells necessary (as well as Animate Dead and similar abilities)? This would explain the other undead there. He'd need a high enough Willpower for the Spell Stitching to work, and a high enough Charisma to make use of the Power of the Dead ability. He's the boss, but not the dragon of the encounter... he just always knows where the party is, and can direct attacks against them. Thus, they can never hide (unless they have Darkstalker of course).

As for the dragon of this encounter, this is a pirate thing, so why not have a fearsome pirate king? Necropolitan Rogue 3/Fighter 2/Scarlet Corsair 5 with Imperious Command would be a scary enemy... he could send in the minions for the final attack, then jump in and use Imperious Command to force enemies to cower.

JaronK

[Iorthol]

I'm on a friend's computer so I needed somewhere to keep notes.

NEW IDEAS because of the poster's delightful ideas~

Tomb wardens originally placed to guard the crypt, corrupted by the boss of the dungeon with cysts and magic and stuff.
Spellstitched ghouls and ghasts. (Killing them softly, with magic missile)

Boss: Warlock 8 Lich (Yay hideous blow!)

[Daftendirekt]

Boss: Warlock 8 Lich (Yay hideous blow!)

Can warlocks even become liches? If so, not until level 11. Caster level 11 is one of the requirements for becoming a lich.