I'll go with that for the language and telepathy. Any more special abilities?
We're not missing anything from the original monster as far as I can see, although I would like to add a few more tweaks.
Firstly, I think we should increase the CL/ML of the SLA/Psi powers from 6th to 8th, since (a) it matches their HD and (b) it's the minimum CL for a sorcerer to use
phantasmal killer.
Come to think of it, didn't I suggest that before? I certainly remember intending to.
Secondly, their poison is "Contact" but is delivered by a melee bite, which would normally be an "Injury" poison.
Presumably that's a reference to the original flavour saying "
tentacles around the mouth cause a stinging and burning sensation upon contact with flesh (save vs. poison for each bite that hits; failure yields a -3 penalty to armor class, saving throws, and to-hit rolls) that lasts for 3-12 turns."
However, the bit before the bracket that I've highlighted in blue implies they don't need to bite or even draw blood to poison an opponent.
Shall we modify the SA so they can poison an opponent by maintaining a grapple or making a touch attack?
Heck, how about we let them use their feeding tentacles to seize & poison foes in combat:
Attack/Full Attack: Bite +10 melee (10d10+6 and poison) or tentacles +10 melee touch (grapple plus poison)
Improved Grab (Ex): To use this ability, a cessirid must hit with its tentacles attack. It can then attempt to start a grapple as a free action without provoking an attack of opportunity. If it wins the grapple check, it establishes a hold and affects its opponent with its poison.
Poison (Ex): Contact or injury, Fortitude save (DC 18); initial damage sickened for 1d10 minutes; secondary damage 1d6 Dex and sickened for 1d2 hours.
A cessirid's tentacles constantly ooze poison, which trickles back into the illithidae's mouth. Any creature hit by a cessirid's bite must save against this poison. An opponent must also must save against this poison every time a cessirid makes an opposed grapple check against them. The cessirid does not need to win the grapple check, since mere contact is enough to poison its foe.