This has probably been noticed before, but there's some decent synergy going on between necrocarnate and thrallmaster.
The main trick here is at around character level 10, since a thrallherd at that level will have about ~10-15 believers who appear magically (psionically?) each day. Using necrocarnate, you and your thrall then spend about 15 minutes a day to kill off your believers in an unholy (unpsionic?) ritual, granting you an extra 10-15 essentia per day, which means that with your low essentia cap pretty much all of your soulmelds and feats are going to be fully charged all the time.
I came up with:
LN Azurin Psion (Telepath) 3/Incarnate 2/Soul Manifester 3/Thrallherd 1/Necrocarnate 1/Legacy Champion 10 (advancing Soul Manifester), with an end result of ML 18 (14 actual, 4 from Practiced Manifester), Meldshaper 14.
Legacy champion isn't particularly necessary, but the basic chassis is much nicer than Soul Manifester, with d4 -> d8, 1/2 BAB -> 3/4, and 2 skills/lvl -> 4 skills/lvl. And there are some decent psionic legacy items.
The main problem I ran into is that the build is very feat-tight, and very MAD (needs a high cha for thrallmaster, 14+ wis for inquisitor feat, high int for psion and all the knowledge skills required, high con for meldshaping, and high str or dex for any physical attacks). I'm also not too experienced with either MoI or psionics, so I didn't know where to take the build. Could make an archer build with zen archery maybe...