--For the Aura Mod slot--
[Worthy Comradery] +75% squad weakpoint critical chance. If you don't have it yet (New with the 1999 update) growing power works instead. Not yet on overframe.
--For the Arcane Slot--
Overframe also does not currently have the new Arcane Crepuscular - While invisible, gain +30% Ability Strength and +3x Final Critical Multiplier. This is a better option for Molt Augmented, or could be taken over Energize if you find you don't have energy problems or use Zenurik
--Playstyle--
The Neutralizer is a very strong sniper, and this build utilizes it heavily. Has a powerful and scaling passive -Weak Point Kills increase [Cyte-09]'s Weak Point Critical Chance by 1% up to 300% for the duration of the current mission. Still works very well as a sniper platform for a Sniper primary, and for other weakpoint focused weapons.
Exalted Weapon: [Neutralizer] 2 Forma Apex Neutralizer Build- Deadeye Reverb//72 million red crits//Steel Path//Solo
[Cyte-09] Is a very capable weapons platform, and can easily clear steel path content up to endurance. Any headshot weapon will work, and you can opt to just use the [Neutralizer], which scales very well outside of level cap. The ricochet effect is particularly useful for getting multiple head shots, as they tend to hit the head, but can swapped for Roar if your looking to make the ultimate sniper platform for your primary.
Keep Evade up at all times. Headshot kills in a group with [Neutralizer] give up to 30 seconds duration, also triggers [Intensify] if you are missing health. Can swap [Growing Power] for [Combat Discipline], for consistent [Archon Intensify] activations, but only gain 5% ability power over just taking [Growing Power]. If you don't have [Archon Intensify], it's not super important regular intensify or precision intensify will suffice, down to preference.
Staying alive: Even with invisibility, [Cyte-09] is not a very durable frame. You want to stay scoped as much as you can, and that makes it hard to constantly be aware of AoE. The best way to stay alive is to be in an adjacent room, Pulling off headshots highlighted by seek, with the extra punch through it also provides. If your in a squad, you rarely want to be in the same room, as they can unintentionally draw fire or aoe attacks on you while invisible. [Augur Secrets] is there for some quick shield [Regen], negative efficiency helps it to some degree when in a "oh shit" situation.
Seek is your friend. It makes headshots easy, makes them stronger, lets you shoot and see through walls, has excellent range and duration. Use it on everything you shoot.
Resupply as needed. Ideally have it up all the time. In many cases, you'll find that your one shotting enemies without it, so in those instances, it might be better to save the energy. It's helpful to match the damage type against enemy type, but is often overkill. Can also fill in a status you need with guaranteed application. Seems to be really strong, creating it's own damage instance. but I understand the temptation to Helmith Roar over it, given how much the rest of his kit benefits from the extra power and damage, and how well it fits into the stats of the build (high strength, duration) *Note Resupply does not apply to incarnon weapons while they are in incarnon mode, making it less appealing when using a full incarnon setup. If your looking for a weapons platform for incarnon weapons (which [Cyte-09] will do very well) Then Roar becomes essential, and should be taken over resupply.
Flex Options
If you don't have Arcane Energize one option would be to throw on an extra forma, and swap [Augur Secrets] for [Equilibrium] and add in molt [Vigor].
Additionally if your just going for raw damage, and don't have the new arcane yet, Molt Augmented can be swapped for Molt [Vigor] But I find the extra duration is a nice QoL for keeping cloak up.
If you don't have [Archon Intensify], Normal [Intensify] works nearly as well. Can also use [Precision Intensify] for the super juicy [Neutralizer] multiplier, but will be entirely overkill outside of endurance and specific boss encounters. If using roar over resupply, I would stick with normal [Intensify] if you don't have archon, Unless your putting roar on the 4, in which case [Precision Intensify] is best. I included [Archon Intensify] because it doesn't require an extra forma over normal [Intensify] and is technically better. On higher end runs however, its unlikely to activate, as most things will kill you if they hit your health outside of using combat discipline.
Focus Schools
Maduari -for the extra power strength, the cast time isn't super important but is a nice Qol, and makes it decent for void cascade.
Zenurik -would be a good option if you don't have arcane energize or are having energy problems in general. Cyte isn't a energy hungry frame for the most part, even with a negative efficiency build, Zenurik will offer another alternative for energy related issues, but should be enough on it's own without the help of other mods.
Archon Shards
Benefits the most from Crimson shards and power strength, but Cast speed from Amber shards is a nice Qol, up to two.