ToME: the Tales of Maj'Eyal

Having already beaten the game twice, I find Insane mode to be the obvious next step. Unfortunately, it's immensely frustrating. The level of difficulty feels appropriate for, say, 90% of encounters but some of them become far harder due to the way certain monsters or talents scale with level. Here are some examples of what I mean:

• A rattlesnake is a common starting enemy. In Insane, it has 36 Str, 34 Dex, and 16 Def - I doubt any melee characters can take one in a stand up fight, which means stairscumming is the most realistic option for killing them.
  
  Other starting enemies are even worse. A minotaur can confuse you at range at >100% confusion (even if you have confusion resist gear), so you can't even let one stay on screen. A spitting spider can kill you in one hit if you've used your wild infusion already. An assassin can take you from full to dead in one round (and even if you survive you're likely to be slowed/iced/poisoned). All of these can show up starting from Trollmire 1!
  
  Trollmire, though, is comparatively easy. Getting out of the undead starting dungeon is nearly impossible - glancing at the character vault, only 6 characters have managed to do it.
  
  Once you get out of the starting dungeon, wilderness encounters are so high above your level that they're suicide (for dragons/adventurers - presumably orcs, though I haven't tried). Dying from full HP in a single round is the norm.
  
  That kind of kill is especially pronounced for damage classes, like corruptors/archers, who can already hit for very large amounts of damage in the normal game. In Insane, they have so many levels on you that walking around a corner can get you killed instantly. I assume this is the case with berserkers, too, though I haven't gotten far enough to run into any yet.
  
  Most quests and bosses are dramatically overleveled, but some remain doable. Others don't. For example, I did the Zigur quest around L18 and got L40 monsters in the pit!
  
  This boss effect is worst when talents scale to a point where they have unexpected effects. The Weirdling Beast's Acid Splash - normally not that big a deal - was such a large Acc debuff that I could only hit him once, and then I'd have to wait for it to wear off.

I think Insane should remain depressingly difficult, but I don't think the examples above are anything other than quirks of how talents scale or monsters level. I know that I'd have a lot more fun if Insane were just hard, rather than feeling arbitrary.

The only issue I find with Insane isn't exactly about the difficulty itself but the way some talents scale linearly to ridiculous overpoweredness at very high levels.

I'll just give you an example I found while playing:

A random unique Cursed:
Level 30 Weapon mastery - Although 30 might seem absurd, it's ok because weapon mastery has diminishing returns:
getDamage = function(self, t) return math.sqrt(self:getTalentLevel(t) / 10) end (around 173% bonus damage)
Level 15 Slash - local multiplier = 1 + (0.17 + .23 * self:getTalentLevel(t)) * getHateMultiplier(self, 0, 1) (362% bonus damage, almost a x5 multiplier)

To cut the story short I got oneshotted by an attack doing a pre-mitigation damage around 4k or something.