Personally I just find the neogi and their kind of evil super bland and uninteresting, literally their slaves are more interesting then them, although if you want a good punching bag villain, then they are alright in that regard.
That's what I mean by "too much and too little." The evil is always ramped up passed 11, but there's none of the personality and complexity that some other mega-uber-evil dnd monsters have besides some charmingly weird aesthetics.
I've had some ideas for how to reimagine the neogi. Most of which more or less come down to three things.
1. The neogi are inhuman in a way that forces them to have developed inhuman values.
I like the idea that rather than having been conquered by them at some point in the past, the umber hulks and neogi are actually co-evolved to be each other's brawn and brain; thus, giving orders and making decisions for other creature's is literal instinct for neogi. Additionally, their life cycle requires the total degredation and eventual agonizing death of one of their own kind; there's a callousness, hierarchy, and sense of "life is cheap" that you can't avoid if that's your biology. The "life is cheap" part isn't helped by them being an r-type species with vicious, nonsapient predator newborns either.
But nonetheless, these creatures were able to form a functional society. One advanced enough to be capable of building and operating magical spaceships, no less. How did they do that? There must be philosophies and morals here. Harsh, bleak ones, perhaps, but still ones that encourage cooperation, interdependence, and in-group loyalty. They have an idea of what makes a neogi a good person or a bad person. It doesn't totally overlap with how humans would judge such things, but it isn't
totally unrecognizable or inimical either. You can be friends with a neogi. As individuals, neogi don't have to be evil at all, but it's very hard for a society of them to not be.
2. The neogi might be thieves and slavers, but they are primarily, before anything else,
merchants.
The whole "neogi are hated by literally everyone" thing is irreconcilable with their alleged way of life. They must have people who they trade with. You don't give your trading partners reasons to hate you, if you can help it. In most cases, if you meet a neogi, it won't be trying to eat you or enslave you; it will be trying to sell you something. And they really do sell
everything. With their flying ships and foolhardy ways, neogi have truly been everywhere, and can get back and forth between anyplace and anyplace else with astonishing speed. Need a magic item? A crafting material? A piece of information? If they don't have it in their hold right now, they can be back here with it in a month if you pay a tenth up front! They sell shady stuff up to and including people, yes, but they also sell
nonshady stuff of every kind.
Are you willing to dirty your hands by doing business with these things? Is your situation so desperate that you can't afford NOT to do business with these things?
3. When it does come to combat, they need more interesting mechanics than "3/day mind control." I've been thinking about making them nonmagical by default, and instead giving them a moveset stemming from the "designed by nature (and/or the gods) to boss giant stag beetles around" concept. They've got leadership abilities. Think 4E taclord kinda stuff, with actions that give their minions extra movement and attacks and stuff.
I've also toyed with an idea that sort of borrows from the "lolenslave" powers of third edition onward, but is more flavorful and less like every other aberration. I'm thinking they have a sort of Bene Gesserit-ish commanding voice ability that they can use to make people perform short, reflexive actions (like a watered down version of the Command spell). Meanwhile, their venom (delivered either by bite or more commonly by poisoned dart) is a narcotic that gives you a penalty to mental saving throws. Thus making their voices more effective and also making their umber hulks' confusion powers more likely to work.
So, instead of a fight with neogi playing out exactly like a fight with mind flayers or whatever, it's a battle against big brutes that each have a little low-hitpoint action economy ratfucker riding on their shoulders. Maybe make it so they can use their umber hulks as body shields unless you flank, surprise, or attack from above, thus giving the players some interesting tactical options.
