Having messed around with the rework for Nyx for a little bit I'm a tad disappointed. Please, forgive my wall of text in advance.
First I thought the passive would be useful, but it really is negligible of an impact. The accuracy debuff is really really weak to the point that I question if it even works properly. I die just as quickly and it's definitely no Titania Dust. Even if it did work well, it's counter to the changes of her Absorb demanding she take damage.
The changes to Mind Control are really good, and for an ability that costs little energy, it's one of the most damaging abilities in the game. Or it would be, if Mind Controlled targets had any sense of priorities. Rather than casting Nidus' 1 down a hallway or Octavia's 1 on a choke I'm left with a damage dealing ability, that while strong, works about as well as the enemy feels that day.
For an ability labelled "Mind Control", there's not a lot of 'control' going on.
The change to Absorb that lets her gain a damage buff after detonating it is very interesting. I like it, but it goes away after using Absorb before the lingering absorb duration ends. It also is pretty clunky if you intend to use it to boost the Mind Control'd target. Not only is there a long animation to deactivate absorb, but you also have to cast Mind Control on something, then also shoot it. You are very likely dead after all of that, unless you maybe Cast Chaos to cover yourself. More on why that isn't necessarily useful.
Lingering Absorb lacks finesse is what I'm saying. It's clunky but I love the idea.
Keeping with the theme of being clunky, Psychic Bolts' changes are amazing but still clunky in execution. I question why we are limited to only 6 enemies, not just per cast, but in total. Not only does this restriction really hold its potential back, but it makes recasting it require an uncast time.
Lastly, even with her passive, Chaos isn't reliable damage reduction. I know it's not supposed to be Iron Skin but enemy AI as dumb as it currently is should not be what saves the player. Especially if people want to see smarter enemies. It would be real nice if there was a way to directly influence whether or not you or something else is targeted. Nyx is in a really strange spot right now I feel. I do feel she's trying to be forced into the same nich Glass Cannon character as Banshee. No invisibility, but has CC and damage potential. Except, Banshee isn't a very good frame to emulate on their own. Banshee's strengths largely come from her really really strong augments. Banshee on her own is kind of weak.
Nyx doesn't have any of that. No meaningful synergy, and clunky mechanics.
She functionally radiates targets, but without the radiation proc. Radiation is really strong with Disarm. Not just any disarm. Single target disarming is kind of weak. We need enmasse disarm on demand. It would be great if there was a way for Nyx to force all enemies affected by her abilities to be Disarmed. Not with a passive. Give her that control.
Same thing with Mind Control. Let me pick what the Mind Control target guns down or focuses on.
So to tl;dr: Abilities Clunky, streamline it so it all flows really well. Take advantage of Disarm+Friendly Fire grouping enemies up for AoE attacks by adding a way to disarm lots of enemies, something you can do with radiation+disarm and indirectly is a form of damage multiplication. Give her control over the enemies more. Such as ordering the Mind Control Target around, or having Chaos'd targets focus on the Mind Control target.
Making it less clunky would let her be less vulnerable, given her paper thin defenses. Giving her more control would justify the restrictions on Psychic Bolts, and grouping enemies up is a form of damage multiplication anyhow. Absorb even is an AoE. The recipe for a strong and unique frame is there. Just add the spice.
EDIT: Ways to go about it would include a Charge Mechanic for Chaos that lets you cast a Disarming Chaos. Without an Augment. Can you imagine enemies literally losing their minds, screaming, throwing their guns around, drawing their melee weapons and wailing on eachother? Because that's what I think about when I think of a warframe like Nyx.
Casting Mind Control on an enemy Affected by Chaos should also draw all aggro of nearby affected enemies to the Mind Control target. This should feed into the damage multiplier too. If there's enough enemies, and strong ones, you don't even need to shoot at the MC target yourself. That's how you could get the ability to scale safely too. Since MC enemies are immune to damage until after the duration ends this is a fantastic way to get the MC target killed once the duration runs out and ensure its damage increases.
Uncasting Mind Control remains by holding it, but tapping to recast should still let you command the MC to attack a marked enemy. Also manual uncasting should always disarm the MC target. There's a lot of sitautons where one could manually uncast it and a bombard just rockets you immediately in the face despite it being the last enemy alive.
Psychic Bolts should be able to spread if we can't recast it freely. Perhaps nearby enemies affected by Chaos can suffer the effects of Psychic bolts if the current duration is in effect and one of the old afflicted enemies die.