Well ... carnivore brought "Mind Mage" over into his 3.5 Psion guide,
and non-updated 3.0 material was supposed to just transfer.
This is somewhat illogical, because clearly the Mind Mage has all sorts of psi 3.0 weirdness going on.
Mindflayer 15 is kinda weak sauce.
The little mindflayer baby suckers in CPsi, are better.
Not because they appear better at all, but because they're just a few hd.
Stick more class levels on them.
You might protest that they have no LA number.
That's OK because a racial progression for mind flayers exists in Sav Species.
Mix and Match.
Then that nifty Illithid PrC is
mandatory.
Just a matter of getting there efficiently, and how many clamps the DM wants to put on it.
Most custom of classes. Most brain eating of classes.
Thrallherd is a good idea, at this point.
You can't go wrong with that combo ...