Building an mindflayer boss fight for a D&D 3.5 game

Building an mindflayer boss fight for a D&D 3.5 game.

Party consists of five level 6 characters:
Elan Psion (shaper)
Azurin Psychic Warrior
Human Crusader (spiked chain based)
Human Swordsage (shadow hand based)
Gnoll Totemist

This is going to be a big boss fight (CR 9).
I want to use a mindflayer (psionic variant) with grimlock minions.

Ideas:
The party is sneaky, so it might be a good idea to give the mindflayer the Mindsight feat from Lords of Madness.
The party can dish out a lot of damage, so I also need to make the mindflayer tough.
Maybe swap out Improved Initiative for Psicrystal Affinity (nimble personality) and give the psicrystal the Mind Sight feat.
Then I can swap out one of the mindflayer's level 2 powers for Share Pain and do the Vigor +Share Pain+Psicrystal combo.
Larval Flayers is a flavorful power, and it could add a second wave of minions to the encounter when the grimlocks are knocked out, but it is kind of a weak power and a waste of power points. What I may do instead is give the mindflayer a Dorje of Larval Flayers and points in Use Psionic Device so it has something to do when its power points are all gone.
The grimlocks can get Thrall Bred instead of Track, and some other feat instead of Alertness since the mindflayer already has that covered.

Terrain will have features that impair visibility, such as fog or darkness, since none of the monsters need to be able to see.

Suggestions?

i-is that semen???

>Obligatory don't play 3.5

As a DM, you can change the Mindflayer however you want. Feel free to give them at-will Larval Flayers if you're worried that you'll need to sacrifice any power overall for fluff. Also, it seems the party is heavily melee. Use things like pits and copious amounts of difficult terrain.

Some more specific questions for all of you:

Should I use just four grimlocks, or two grimlocks with templates?

If the psicrystal has the same skills as its master, then can the psicrystal use a dorje?

I'd like to give the mindflayer tentacle extensions from The Illithiad, but I can't find stats for those in Lords of Madness. Any ideas?

My campaign has wand chambers from Dungeonscape adapted into dorje chambers. If the psicrystal can't use a dorje, I may put dorje chambers in the mindflayer's tentacle extensions. And maybe stick some poison wells and weapon augment crystals on there for good measure. What's a good way to fit that into the gear budget?

>>Obligatory don't play 3.5
3.5 is actually prettty fun with Psionics and Tome of Battle.

Good idea, user.
Murky pools of water would be appropriate.
I could have the mindflayer sitting on a raised platform in the middle of a underground lake where it can draw line of sight to everyone in the chamber and pick them off with ranged attacks.
Grimlocks around the pool would block any PC's that try to get too close.

I'm one of those DM's that actually bans the PHB.
ToB, XPH, and MoI classes only.

How many grimlocks are you going to use op?

It would take 5 base grimlocks to equal out a CR 9 encounter and your players party is overall a 6.8. putting it right at point where it goes from Extremely Difficult to Impossible.

Consider knocking it down to three grimlocks with 2 levels of warrior, giving the mindflayer nothing beyond basic kit and the CR will still be 9 and the grimlocks will be more of a challenge while not being blasted to oblivion in round 1.

Also probably want to have the mindflayer in difficult terrain, making it hazardous to try and take him out first and also a slightly higher challenge.

Also note that this should be a very difficult fight and should have used a bit of resources but not have them run dry for the day.

It's just squid juice. Yes.

Three sounds good.
I don't mind the grimlocks getting bumped off quickly as long as it buys the mindflayer some time to do something cool. Again, I intend of on having the mindflayer generate waves of Larval Flayers throughout the fight to serve as reinforcements. I'm just trying to figure out the best way to go about that. I could just straight-up give the mindflayer at-will Larval Flayers, as suggested. If I want to play it by the rules (so I don't have to put up with one particular player groaning) I could give the Linked Power feat, and have the mindflayer use the Larval Flayers power linked to something else every round.