Assuming that you want to use one psi school (TM), with no utilities, then it's Sheepherder's fine crafted build that will surely satisfy you:
https://stygiansoftware.com/forums/index.php?topic=6116.msg32140#msg32140It's based on evasion.
If you allow yourself to use traps, then something like this should be feasible and enjoyable (if you have the patience to prepare fights laying traps in stategic spots while sneaking around undetected, and sometimes attracting enemies into a death zone you've just created with tnt for example) :
https://underrail.info/build/?HgMHBgMDEAgAAAAAAADCoAAAABk2Xw06UgAAAMKgAABFOScrP8KGKjBkwrzCh8KIVyRywrffvw (feat not in order but I would take the 8 first in this order personally)
You could take Grenadier and Three Pointer, but you'll end up not using Psi that much if you do so...
Explanation concerning crafting :
81 bio with no bonuses means you can extract fusing enzymes while fishing and creates (enriched) super health hypo with a boning knife (+4 bio, commonly dropped by Lurkers) and the bioinvestigation belt (acquired at the end of some Tchortists' questline). You can set it to 100 right away if you don't want to bother, the enriched ones advantages are not reliable anyway... You'll be able to craft bullhead pills, psionic accelerator, Psi Reinvigorator, juice, third eye (for lore and secrets)... You could raise bio and use poison too and maybe take Hypertoxicity if you think it's fun.
20 chemistry to have gas grenade for beast fight... Though it might not be this useful with TD spamming and continuum ripple and traps (can't tell, never tried myself). 10 is required to create inhalant.
96 effective mech with all bonuses for regenerative/strudy laminated psionic vest assuming 160Q component and 100Q psi beetle carapace... Raise it to 128 if you want to use super steel instead of laminated panel at the cost of +5%(additive) armor penalty.
144 effective tailoring with all bonuses for 160Q vest + 160Q black cloth
167 electronics for headbands, shield emitters and personal cloaking devices. >105 effective with no bonuses mean you can craft EMP III mines whenever you need to (if you have the components, obviously.)
Traps: 25 is required to take quick tinkering and use a bear trap during combat, which can serve as a chokepoint control ability (very important for you because of the delayed nature of your main attack, namely Temporal Distortion), 75 is required to use MK3 EMP which are really useful against bots, especially Naga Protectors and Dreadnaught, 95 to use anything you want.
Throwing: 124 effective for max precision, put 160 points in it if you take three pointer (if you do so take grenadier too beforehand)
stealth : the more, the better
Mercantile: 92 effective, means 95 effective with fairly common Underpie (food). This unlocks the 2nd special inventories for the most important merchant for you as a psion. 140 effective (reached with +2 int from hypercerebrix and underpie) could provide you with late games that mainly provides you with more money... that you won't need at all at this point as a psion anyways.
Additionnal feats you could include : invest 75 points in Thought Control and take Locus of control to alleviate though controllers' threat or other incapacitation effect ; Grenadier and Three pointer, as mentioned, Paranoïa for stealthy enemies detection even though it won't suffice past some points in DOMINATING, Mantra (good but not necessary), Nimble is cool but not necessary because you'll wear a 30/40% penalty armor, Pack Rathound is a very nice QoL feat for a low STR trapper.
Hope it helps a bit.
Oh, about spec: 10 points in Continuum Ripple should be obvious. 5 points in Optimisation for the rest seems nice.
WARNING: if you're new to the game, this way of playing it may reveal a bit frustrating to you whichever of the two preceding builds you choose.
Nota: you have tons of sparepoints, you can use them for throwing would you choose to invest in it at all, lockpicking, hacking, persuasion... Higher threshold are respectively : 130, 135 (130 without tools), and 110. Check Destroyer's guide for more precision or check out options in extra in Epeli's tool (you can add +2 int with some drugs in the game and the rest are options you can select in Extras)
Nota 2: if you don't want to go pure TM, check out Knifegaf's build showcase on Youtube about the TC/TM build.
