I have been playing Ghost type PSI Snipers since release and they work well overall, only really struggle with Death Stalkers if you are reluctant to rely overly much on cheese play. I have not played a PSI Sniper in Expansion content but I had no problem clearing Hard with him. Dominating needs careful play though due to 3 Con. Not recommended for reckless or inexperienced player but loads of fun. Only type of enemy that is a real pain to deal with are aforementioned Death Stalkers, have to cheese those disgusting creatures. 7 Agi,max stealth and Interloper lets you circumvent a lot of enemies. Recommended to kill Lurkers on the Map with Blaine's shop and on the map east of his shop after you are done reclaiming the outposts. I only ever play Oddity, no idea if this plays well on Classic.
This builds biggest advantage is that it can do almost anything including silently killing entire maps without ever alerting any opponents thanks to TC and it can pass most persuasion and mercantile checks. With buff food and items can pass most attribute checks except dexterity. There is very little this character cannot do. You can opt to swap one of the feats out for Paranoia to maximize detection levels. With it, level 16+, 100%+ Detection goggles, Stuffed Bat food and 250+ Sneak you have a shot at detecting Death Stalkers before they can open up. Your Snipe and Aimed Shot damage won't be as high as a pure Snipers but those two abilities deal such absurd damage that shaving off around 10% damage from non-maximized perception has no real noticeable effect anyway except a few super high HP targets.
If you want more PSI and less Aimed Shot you can swap out Shooting Spree and Critical Power/Sharpshooter which only really help Aimed Shot and nothing else. The biggest problem I had since the beginning is that Aimed Shot and Snipe scale completely differently which makes Critical Power and Sharpshooter not high value feats like they are to other purely crit focused builds. Though it is nice that there are builds which are not just about stacking crit and crit damage which far too many builds are.
Level 1
http://underrail.info.tm/build/?AQUDBwMICAYPAAAAAAAPDw8AAAAAAAAADw8ADwAADysBOd-_Early levels you should get a Vigorous belt and use HP buff foods. Those 40-50 hitpoints go a long way to alleviate your biggest weakness, survivabilty. Later you switch to Medicine Pouch and 40 HP food from the expansion. Being able to use your medicines with only 2 AP is just too good to pass on with this build which struggles most with AP management. Due to lack of a good rifle at the start of the game you are much more reliant on PSI which is why the build starts getting Tranquility and Force User Feat first. PSI beetles in warehouse need some bear traps and caltrops. Caltrops are very effective against them by the way. I do not like to use molotov cocktails without having a shield. They can misfire easily and if you start burning yourself you can effectively reload.
First two attribute points into perception for Snipe at level 8. Next two points into into will for LoC at level 16 which is when you can relax a little. Getting Hacking to effectively 60 without Haxxors to hack into security computers is hugely benefitial in Depot A. Adjust lockpicking to the current levels you want to pick buff with eel sandwich and Jackknife in hand.
Level 30
http://underrail.info.tm/build/?HgUDBwMKDAbCoAAAAAAAwqBYYgAAZGQAAADCoMKgAEY1AEUrATk_FCo1fsKHIcKIHSRLM8K1wrl44pyaCuKitQLisaAD378http://underrail.info.tm/build/?HgUDBwMKDAbCoAAAAAAAwqBYYgAAZGQAAADCoMKgAEY1AEUrATk_FCo1wofCiAIhJB0oBcK1wrl44qK1AuKxoAXfvwMore PSI heavy variant with Paranoia. Aimed Shot becomes a filler ability when you are out of stealth, out of PSI and PSI booster on CD. Stronger against crit immune enemies like Bladelings since Aimed Shot is utterly worthless against them but Neural Overload is quite strong against them.
Level 30 build feats are not in perfect order since I have not played a PSI Sniper yet in the expansion. As you can see this build only really needs Mechanics and Electronics to make guns, shields, stealth generator, taser, etc. Vital to make are NV goggles with enhanced damage for special shots. Also craft sniper rifles with smart modules and rapid reloaders. Use the standard scope for extra precision. If you feel you do not need it you can use the crit damage scope, though those do not benefit Snipe at all. There are enough leftover points that you can invest into for example biology if you want to make some medicine. Though due to Snipe and Aimed Shot your PSI consumption is not nearly as high as a pure PSI builds so going early into biology for PSI boosters is low priority. This of course leads to the fact that PSI cost reduction is of little value. Nimble comes late because it is then that the 10%/15% penalty from your overcoats start taking a serious toll on your overall stealth value. At around 200+ sneak you effectively gain 20+ or 30+ stealth, depending which type of overcoat you are using. If you feel that it is not worth it you can get Ambush instead. While the crit is fairly pointless the reduction in opponents Evasion is what makes this feat interesting to this build.
Buy ninja tabis and balaclavas, your self made ones are not that much better than bought ones anyway. You can get really good stealth overcoats from the Black Crawlers, the guys you are taking out together with Gorsky. If you want to do those missions, then push your persuasion to 70 with pie food and go in via Bob's credential which is much easier than going through retarded Death Stalker infested underground. Bear traps are your best friend, have at least 5, better 10 even, at all times. Either use them to deny certain areas, or set them around corners so enemies cannot detect them before walking into them. Kiting is vital to this build. Do not let melee enemies come close. High priority targets are enemy PSI users, crossbow users and snipers. Other weapon types are not nearly as dangerous thanks to your shield and overcoat. Stealthed enemies are almost never a problem unless you bump into them. Except for Death Stalkers of course. Hate those fuckers in case you have not noticed
Arena can be a bit tricky. You cannot start in stealth and are prone to go second. Get again Vigorous belt and HP buff food and adjust your armor to the enemy. When in doubt ask Garry, he gives you a basic rundown of your opponent. Oh and turn on your shield before arena. It helps having it up right at the start.
