Cutter

General overview

Cutter packs a huge punch for her rarity. She's one of the few melee units who can hit drones, and her kit has options for single- and multi-target damage. Her main downside is that she has to constantly attack to charge SP, which is usually only possible if you have her directly taking hits (a difficult proposition, with her mediocre defensive stats). She also has no way of attacking drones outside of her skill, unlike archetypes like ranged guards, who can target them with normal attacks. These downsides shouldn't overshadow the fact that she's an incredibly strong unit with DPS that's comparable to her higher rarity counterparts.

E2? You should E2 her. It's cheap, and the difference in her performance with and without masteries is night and day.

Game modes

Cutter is pretty good in every game mode. Her damage is good enough to justify using her in high-risk CC, not to mention she can kill drones in a pinch. She's also insulated from some contracts, like the ones that slow down SP recovery. In IS, there are quite a few modules that make her incredibly broken, namely the offensive/defensive SP ones, ASPD buffs, and Hand of Shredder. And she's a good pick for SSS because you can easily abuse vanguard buffs for the free SP generation.

Talents

Talent - Photoetched Marks

E1 Normal attacks have a 12% (+3%) chance to restore 1 additional SP.

E2 Normal attacks have a 20% (+3%) chance to restore 1 additional SP.

Her talent synergizes well with her archetype because it lets her wring as much SP as she can out of her attacks.

Skills

Skill 1 - Redshift

Skill effect: Immediately attacks random enemies within range 4 times with throwing knives, each knife dealing 280%/340% of ATK as physical damage.

Note: Knives are thrown consecutively, and targets are selected as they're thrown. If something walks into range while she's unloading her skill, it counts as a potential target.

Skill range:

Overview: Skill 1 will outdamage skill 2 if it's only being used against one or two enemies. Really, I think it's best considered as a single-target damage skill, because there is a world of hurt awaiting any enemy that gets all 4 knives thrown at them. The range is situationally both a blessing and a curse, so you might have to face her in a weird direction to make sure she's guaranteed to hit the enemy you want.

M3? M3 gives this skill a huge damage increase, and the 3 SP cost reduction is a lot for an offensive recovery skill. I think Cutter is a fantastic (almost mandatory, even) M6 candidate, so which skill you M3 first is a matter of preference.

Skill 2 - Crimson Crescent

Skill effect: Deals 380%/450% physical damage to up to 6 nearby enemies; damage is doubled against aerial enemies

Skill range:

Overview: Great AOE damage with a huge range, and can OHKO weaker drones. This is a much more reliable multi-target damage source than skill 1 because it's a guaranteed hit on 6 targets vs. an RNG-dependent hit on 4 (with better multipliers to boot). You do need to be a bit judicious with it if you want to use her as a drone killer, but she's not attacking and charging SP constantly.

M3? Everything I said about skill 1 applies here. Some might prefer to M3 this skill first because it has a little more utility via the drone targeting, but that really depends on the player.

Module - Replaceable Tool Set

Level 1: Attacks ignore 70 DEF

Level 2: Talent Upgrade: Normal attacks have a 30% chance to restore 1 additional SP.

Level 3: Talent Upgrade: Normal attacks have a 33% chance to restore 1 additional SP.

Overview: 70 DEF isn't a lot, but her archetype has a harder time with high-DEF enemies than most because DEF is calculated on both of her hits separately, so any bit counts. However, the main reason to get the module is for her talent upgrade, which gives her better odds for free SP. Level 2 is a way better value than level 3, so it's fine to stop there unless you're really passionate about the proc chance being (roughly) an even third.