Fritia - Turbo

If you don't have her yet but want to try her out, Turbo is available as a Trial Operative in Story Chapter SP4 "Sands of Secrets (Main Story // Legacy // Shuozhou // Sands of Secrets)

With maximum investment Turbo is very capable - she deals very good damage, has incredible mobility, and potentially has excellent survivability too, but at the same time she needs lots of investment to be capable, for longer-duration content she absolutely needs her 5* weapon to sustain her damage rotation or else her dps drops off a cliff once her Stamina runs out, and being completely still means that her survivability falls to basically zero when she's actually shooting things using her standard skill or ult, which is ideally the only way she'll ever shoot.
Similarly, her ult just doesn't really do enough damage to be able to clear strong groups in a single shot, but enemy groups usually have at least 4 members so even if her standard skill can kill 1 enemy per shot she frequently needs two damage rotations to clear a single group, which can make Turbo feel clunky to use for normal content.

The Basics

Role: Main DPS
Deals Chaos Damage
Weapon Type: Sniper Rifle
Deals entirely ballistic damage
Mobility:
Whilst actually shooting: Zero
Otherwise: Fantastic

How to use Fritia - Turbo

Dodge to start sprinting and generating Supercharge
(Supercharge = The gauge in the centre of the screen.)
If your magazine isn't full, then you can reload while sprinting
Continue to sprint until Supercharge is full
If shooting at a cluster of more than three targets, use her ult
Otherwise, use her standard skill to shoot three shots

Repeat

(Each rotation takes a little over 4 seconds.)

How to build Fritia - Turbo

Weapon: Sonic Flash / Dream Weaver
Weapon Parts: Max ATK
Logistics Squad: Insight
Basic: +10.0% ATK
+10.6% Crit DMG Amplifier
Special: +8.5% Chaos Damage
Best supports:
Vidya - Celestial Swan
Yao - Nightglow
Marian - Queen of Pain
Eatchel - The Cub

Specifics:

Dodge

When Turbo dodges, she instead starts "Celestial Turbo sprinting" in the given direction.
This is a very fast burst of movement in that given direction, and then Fritia continues sprinting.
This sprinting is faster than a normal operatives regular movement speed.
You can spam this skill to repeat the initial burst of speed, allowing for truly ungodly movement speed, although each burst uses Stamina.

When she's Celesital Turbo sprinting, she gains Supercharge - This is used for her standard skill or ult.
(Supercharge = the three boxes/gauge in the middle of her screen)
Increasing Stamina Recovery also boosts Supercharge

Turbo loses all Supercharge if she leaves the field for any reason.
This includes using the Support and ultimate skills of many support operatives - for example using Yao - Nightglow's ult will cause Turbo to lose all Supercharge.

Note that the circular devices on Turbo's hips have glowing circles around them when she has Supercharge, which is a good visual indicator.
(Note to any devs reading this: Please add an option to remove or reduce the size of these so they get in the way less.)

Maxing her Supercharge takes by-default 2 seconds.

Standard Skill and Ultimate Skill

Turbo can use her Supercharge to fire shots from her Standard Skill or her ult
Turbo is immobile while firing her Standard Skill and her ult.

Turbo's Standard Skill allows her to fire one shot per Supercharge charge - for a maximum of 3 shots.
These shots have auto-lock-on, meaning that provided they lock onto something it's impossible to miss.
Although it is possible to lock-onto something you didn't want to shoot and hence not hit what you wanted (In some scenarios this is quite common...)
Each standard skill shot also has a fixed RoF, fixed base Crit Dmg (of 100%), and fixed weapon Compatibility [of 245%].
Whilst using her standard skill, Turbo kneels down to fire. In some rare circumstances, this can allow Turbo to avoid being hit by just having enemy shots go over her head.

Using her ult fires a single shot that deals AoE damage.
The more Supercharge consumed, the more damage it does.
Note that Turbo will slide to one side as she fires her ult, which can throw your aim off by quite a lot.
If in ADS, she will instead slide forwards or backwards, which can make aiming much easier.
Her ult does also knock targets into the air, which can be used to perma-stunlock non-bosses.
Her ult not having a fixed base Crit Dmg and Compatibility means it benefits less from crit mods, which tends to mean it deals quite a lot less damage than her standard skill.
As such, her ult is only worth using against large groups - for three or fewer targets her standard skill will always outperform her ult.

Note that Turbo's standard skill gets such massive buffs that even against groups you're often better off using her standard skill than her ult.
Many of Turbo's Manifestations buff her standard skill only, or buff her standard skill more than her ult, so the more Manifestations Turbo has the better her standard skill becomes relative to her ult.

Turbo has a Neuronic that allow her to recover Stamina after shooting with her standard skill and ult.
Even with these, Tubo will eventually run out of Stamina unless she has her signature 5* weapon.
When Turbo runs out of Stamina, her dps drops off a cliff, as without her stamina to fuel her Supercharge she can only fire completely-unbuffed normal shots.

Support Skill

Turbo leaps towards the target, causing PBAoE Chaos damage.
The damage of this skill is actually good, but it has a 20s cooldown that gives it very poor dps.

Like most Main DPS-ers, you want Turbo to be used as a main DPS, and she performs very badly as a support.

Weapons

Sonic Flash
-75% Stamina cost of dodge allows Turbo to maintain her standard damage rotation indefinitely.
It also gives a 3-shot Ballistic DMG bonus, which works for both her standard skill and her ult, but sadly doesn't give her ult more damage to compensate for its lower number of shots.
Sonic Flash is a very strong weapon, but it's primary use is that the -75% Stamina dodge cost means Turbo can actually do her standard rotation indefinitely.
Dream Weaver
Some nice Ballistic DMG buffs.
-25% Stamina cost of dodge is very useful, but it's not enough to allow Turbo to maintain her damage rotation continuously.

Not that if you don't have either Sonic Flash or Dream Weaver, Turbo can use any Chaos Sniper Rifle, however her Logistics squad gives her a bonus for Semi-Auto Sniper rifles, so avoid using a bolt-action sniper rifle.
You can use the icons next to a snipers type icon to determine if it's bolt-action or semi-auto (see images to the right).

Chocolate Filling is good because it is an easy-to-get Semi-Auto Chaos Sniper Rifle.

Chocolate Filling
Chocolate Filling is the 5* sniper you get for free from the Paradoxical Lab reward track (reward #30 and #60)
It is a Chaos-damage Semi-Auto Sniper Rifle, and since you can get two copies from the lab rewards you can get it to T2.
Chocolate Filling is not a particularly good weapon for Turbo - Her standard skill fixes her weapins Compatibility, so Chocolate Filling having a high Compatibility stat doesn't help Turbo. Similarly extra Chaos damage every 5s doesn't help her standard skill much, although it is good for her ult.
The Stamina buffs from Dream Weaver mean that Dream Weavers sustained dps is much higher, but for shorter fights Chocolate Filling works very well.

For Weapon Parts Turbo wants max ATK.

Further note that Turbo's Deiwos gives her extra damage based on Ammo Capacity, so higher magazine capacity is useful to her.
Note that this is the "Ammo Capacity" stat, as in Maximum Magazine Capacity, not the number of shots remaining in the current mag.
I.e. Damage doesn't go down as your magazine empties.

Above: A Bolt-Action Sniper
Below: A Semi-Auto Sniper

Logistics

Use Insight squad - it was designed specifically for her and is her best choice.

As mentioned in her weapon section - Insight squad gives her a 30% Crit Dmg Amplifier buff if using a semi-auto sniper, so make sure she is using a semi-auto and not a bolt-action

For stats Turbo wants +10.0% ATK and +10.6% Crit Damage Amplifier.
For the Special talent, Turbo wants +8.5% Chaos Damage

Since her standard skill fixes her base crit damage at 100%, getting +10.6% Crit Dmg Amplifier from a logistics officer gives +10.6% crit dmg, which is very good.

Turbo's Deiwos gives her 3% extra Chaos Damage per Ammo Capacity, with Alignment Index giving her an extra 0.5% on top of that 3%.
Sonic Flash holds 9 rounds, Dream Weaver holds 9 rounds, and Chocolate Filling holds 8 rounds, so the bonus is largely the same regardless of which weapon you use.
Similarly, 100 Alignment Index gives her an extra (0.5%/round) * (9 rounds) = 4.5% Chaos Damage.
Getting her 3 logistics officers to +106 Alignment Index would therefore give her +1.59% Chaos Damage / round = 14.31% Chaos Damage, which is not as strong as the crit mod, as the crit mod stacks multiplicatively with her other buffs, but the Chaos Damage buff from extra Alignment stacks additively with things like other Chaos or ballistic damage buffs.
100 Alignment Index is strong and is a good cope stat, but it's just not as good as Crit Damage Amplifier.

Since Turbo's auto-aim prioritizes enemy weakspots, crit rate isn't a good stat for her, as hits against weakspots always crit, meaning Turbo generally doesn't need any help critting enemies.

For her Special Talent Turbo wants Chaos Damage - it's both very useful to her as well as the only Special Talent that is actually useful to her.

As such, ATK and Crit Dmg Amplifier are Turbo's best logistics stats, with Chaos damage as the Special talent, and Alignment Index as her cope stat.

Manifestation

M1 gives shots from her standard skill +30% weapon Compatibility
For shots from her standard skill Turbo has 245% weapon Compatibility, meaning +30% Compatibility effectively gives +12.24% total damage.
Since Compatibility isn't really affected by anything else, this is essentially a Final Dmg modifier for Turbo
...although since Turbo tends to only use her standard skill, M1 not a massive buff.
Sonic Flash and Dream Weaver have 136.43% Compatibility, so +30% Compatibility gives Turbo +21.98% total damage.
Chocolate Filling has 152.59%, so +30% Compatibility gives Turbo +19.66% total damage.
M2 gives +25% Crit Dmg Amplifier for 5s after dodging.
Since her standard skill fixes her base crit dmg at 100%, this is basically +25% crit damage for her standard skill shots.
This stacks additively with any Crit Damage Amplifier rolls she gets from her logistics though, so it's not as strong as it first sounds.
If you have maxed your logistics officers so all three are giving +10.6% Crit Dmg Amplifier, then Turbo goes from 31.8% Amplifier to 56.8%.
Going from 131.8% crit dmg to 156.8% crit dmg is an increase of 18.9%, which is respectable.
The lower the Crit Dmg Amplifier you're getting from your logistics officers, then the better Turbo's M2 will be.
M3 causes Turbo's standard skill and ultimate shots to ignore 10% of the targets Chaos Res.
Not the strongest ResPen ever, but simple and a nice dps boost.
M4 increases the level of Turbo's standard skill by 1, increasing its weapon Compatibility from 245% to 260%
M5 just gives Turbo +20% ATK if she is equipped with a Chaos Weapon (so... always).

If you want efficiency (good damage without massive investment), then M3 is a good stopping point.
With that being said, if you don't have Turbo's 5* weapon (Sonic Flash) then I recommend you don't invest into Turbo at all - without her 5* weapon she just performs very poorly in endgame content once her stamina runs out (which... it will).
If you do have Turbo's 5* weapon then you can invest as much as you'd like, as all of her Manifestations do buff her. I'd still recommend getting at least M2 or M3 though.

Good Supports for Fritia - Turbo

Turbo works well with most of the games strong support operatives:

Vidya - Celestial Swan (and other resistance shredders)
Celestial Swan and other resistance shredders (Acacia - Kaguya, etc.) that reduce the enemies resistance help enemies take more damage.
If using Celestial Swan, make sure the other support isn't off-element to Turbo.
Yao - Nightglow
Turbo can make full use of Nightglow's ATK, Ballistic, and crit buffs, and Nightglow is a fantastic support for Turbo.
Turbo's higher base crit dmg from her standard skill means that she gets more out of Nightglow's crit dmg weakness debuff than most other DPS operatives.
Note that Nightglow is off-element to Turbo (Nightglow deals Electrical damage)
Marian - Queen of Pain
QoP provides a strong chaos damage resistance debuff, whilst also being able to provide strong buffs/debuffs via weapons and logistics.
QoP is a very strong support for Turbo. Not as good as Celestial Swan or Nightglow, but still strong.
Due to Turbo's very consistent damage, if using QoP you'll likely want to give Marian Deep Sea's Call and Amarna squad due to their much better uptime.
Fenny - Starshine
Turbo can reload whilst generating Supercharge, so Fenny doesn't give any dps bonus by removing the need to reload, and instead Fenny just provides ballistic dmg buffs.
Eatchel - The Cub
A Blitzing Fangs Eatchel provides healing as well as a decent ATK buff.
Not the strongest support these days, but still good.
Turbo has very low HP and DEF, so many players will appreciate Eatchel's healing.

Turbo's best supports are Celestial Swan and Nightglow, although since Nightglow is off-element to Turbo you won't want to use both Celestial Swan and Nightglow together.
Mauxir isn't as strong as Nightglow or Celestial Swan, but is on-element, so Shadow Ka + Celestial Swan is a good pairing for Turbo, as is Nightglow + Kaguya.
Similarly, Eatchel + Celestial Swan and Eatchel + Nightglow are also great pairings.

Turbo's extremely low RoF means that per-shot bonuses like Tess - Phantasia and Fritia - Little Sunshine don't work well with her. They do work, they're just terrible.
(They're also both off-element, and hence don't work with Celestial Swan.)

Since Turbo's auto-aim shots prioritize weakspots, shooting at Mauxir - Shadow Ka's target may actually reduce your dps, since Kebachet is not a weakspot.
Also: Turbo has auto-aim, so the utility of Mauxir providing a stationary target is worthless to Turbo.
Note that Shadow Ka is on-element to Turbo (Shadow Ka deals Chaos damage)