Damage resistance route can work but it's not as effective as it used to be in the alpha version, mainly because metal armors got heavily nerfed and also the range for many PSI abilities was reduced, so in order to get into casting range you'll often be near enough for enemies to enter combat which will mean not getting the initiative.
You can still play a pure, stealthy, not so squishy caster with something like this:
There are two major mutually exclusive psionic paths:
Psychosis which is based on critical hits, big health pool and damage resistance. 10 CON along Conditioning, Stoicism, Lifting Belt and Aegis/Morphine Shot makes here sense.
Tranquility which relies on damage avoidance and enemy kiting. You don't need lots of hitpoints as long as you are able to initiate combat on your terms so a bit of stealth is mandatory.
I prefer Tranquility as it's more easy and fun to play. With high evasion through 10 agility and Evasive Maneuvers plus Uncanny Dodge you're very likely to avoid all damage even if you don't manage to kill everybody in the first round, which is actually doable in many encounters:
Tranquility + Thermodynamicity + 15 Blitz AP (Interloper + Sprint) + 20 Adrenaline Shot AP lets you deal a huge amount of damage or CC in the opening round. Being this AP efficient naturally demands lots of psi points so keeping the PSI cost down as low as possible should be a priority: Muffled psionic headband, tactical vest with beetle carapace (along with regenerative vest to keep the Tranqulity bonus), Meditation and Fast Metabolism - they all help not to run dry too fast. In prolonged battles it will still happen so you'll need to restealth or at least block off enemies long enough to recover PSI points. Regardless of preferred psi discipline it's always good to be able to cast Force Field and Electrokinetic Imprint especially in all those tight corridors so even if this build focuses on TC and Metathermics I advise to raise Psychokinesis skill to 45 in order to qualify for the Imprint.
Speaking of skills this is how they can be distributed:
clickYou will max evasion but you'll require only 40 dodge to pick Uncanny Dodge as it's amazing vs melee (which bypasses shields more easily). It's good to raise it a bit more because each 30 points give you 1 extra attack you automatically dodge. 51 points give you 90 effective points and good quality non-skinner tabi boots get you atleast 60 dodge so if you aim for total of 150 effective points, after armor penalty (20%) you should have 120 which equals 4 additional auto-dodge attacks.
This saves alot of skill points so it's possible to pull this build off with only 6 INT but as usual, you have to rely on home basement crafting bonus and Junkyard Surprise (+2 INT). You need very little mechanics and biology in order to craft the regenerative psionic vest. Super steel fiber (for infused leather) needs only 32 mechanics at most.
There is even enough points to max intimidation. Not only is it used in some conversations, it also turns Yell into a fantastic debuff ability. Everybody affected will have their weapon skill reduced by 35% of your intimidation skill which is directly linked to will, so that's a pretty big precission AND damage penalty. As mentioned before, Tranquility stops working as soon as you start your round with as much as a scratch so your evasion vs enemies ranged skill should be as high as possible. 10 Agility equals 45 movement points, tabis give you around 45 as well so after armor penalty it's 72+ 30 from Sprint equals 102. Evasive Maneuvers converts those into 306 points. Together with your normal evasion you'll have 515+ effective skill for that round! The intimidation debuff is worth almost 100 points so a Level 25, 16 perception enemy will have his 272 guns skill reduced to 172-175 which is far lower than half of your evasion, meaning his chance to hit is 10% (cap). This is the extreme overkill example so it's best to use either Evasive Maneuvers bonus or Yell debuff at one time.
One other very usefull effect of Yell is that it reveals stealthed enemies. Awesome vs. those pesky crawlers.
You don't use any weapons but remember that you can benefit from passive weapon bonuses such as unique Butcher's Cleaver (+20 intimidation) and Kohlmeier's Lucky Knife (-2% chance to get hit critically) so switch between those two accordingly.
It's also possible to make a just as effective build based on Psychokinesis instead of Metathermics. You'll simply replace Thermodynamicity and Pyromaniac with Force User and other Feat of your choice. Keep in mind that Psychokinesis abilities have lower range compared to Meathermics so you'll be in more danger to get hit by enemies. On the other hand less distance also means better use of your Yell ability which has a radius of 8.
Another very versatile build can use all 3 disciplines if you dump CON, max WIL to 16, and bump INT to 8 (to compensate for higher skill need), and replace Fast Metabolism in favor of the other missing psi feat. Psi regenration is 3 pts/round higher but as I'm playing permadeath I prefer that extra health from CON as a buffer for vest regeneration. Fast Metabolism synergizes very well with it plus it makes psi boosters more effective.
