Been lurking around for a while, mainly to browse people's builds for inspiration before reruns through the game, but I figured I'd finally bite the bullet and register so I could reply to this.
Now, I won't go full Sseth-apologist and speak for the entirety of his following, mostly because I simply don't pay much attention to the Sseth tide; I find his videos very entertaining, however, that I can't deny. He might have been vague about some things, but he's also both the sole reason I found out about Underrail and the helpful push I needed to try the game out for myself. Needless to say, after 500 hours of total playtime, I haven't regretted it. I could just be an outlier, too, but, still.
Now, a couple comments on Strat-Edgy's advice and my own advice:
- Early on, before he made his heel-turn from the "bad" into the "good", he was ragging a ton on people normalizing heavy use of the forums and wiki to "build" your build before even playing the game. I can understand that perspective, but, as most people might realize after enough time playing Underail, your build can often turn into a fine balancing act from level to level. Him being upset over not having enough Agility for Blitz on one of his characters until six levels later wouldn't have happened if he'd planned ahead, for example. I don't think there's a single build I've borrowed from yet that I've followed to the letter; for a shotgun build, I ended up also taking feats that benefited sniper rifles so I could handle both short-range and long-range engagements, both groups and single targets. For a psi monk I'm now in the middle of using, I decided against Critical Power in favor of Escape Bonds, which has saved me from many, many headaches whenever someone entangles me in a net or web. In short, to any new Underrail player who might be reading this, don't be afraid to listen along to someone's guidance, but also don't be afraid to experiment.
- A major thing Strat-Edgy seemed to pick up on the later he got into his video is that combat in Underrail often entails more thinking than just running right into a room, guns blazing or fists swinging. Kind of what HulkOSaurus posted earlier. I think I had an easier time with this, inherently, because I've grown up playing other turn-based strategy RPGs like the Avernum and Geneforge. Instead of rushing, learn what the AI tries to trick you with: use chokepoints and cover whenever possible, weaken your prey with traps and mines before closing in for the kill, play as dirty as the game will let you play (and, trust me, you can be pretty dirty). Here are a couple examples that spring to mind. With my earlier mentioned shotgun build, I had enough stealth that I could make a loud noise near one of the Expedition DLC's locust nests, either with a grenade or some other explosion, and then go into stealth. Wait for all the locust to pour out of the nest, and then turn most (or all) of them into chunky salsa with a shotgun burst using 20p or 12p slugs. Meanwhile, in the earlier mentioned psi monk run, I had a rogue industrial robot spawn in the Under-passages... only, it couldn't path to me through the chain-link gate it saw me through, so it went around. As it turns out, it wasn't a fan of the Lurkers who'd set up camp around the corner, so, as they drew its anger, I was given free reign to beat on it a little before running behind cover; by the time it killed the last Lurker, it was already almost scrapped.
A tl;dr of all that would be for any new players to play smarter, not harder; it's insanely satisfying to use areas with ventilation shafts to pick off patrolling/stationary guards one by one. Instead of fighting a massive, extremely dangerous cluster of five or six people, it could just be one or two stragglers wondering where everyone else went.