Alright, I've done the battle twice now, and between this and the original C.S. quest I'm pretty sure I know enough for a quick guide to this so people don't derp this up.
Weaponry (aka Exploiting Weaknesses)
Leave the shotguns at home. You're dealing with moebots here. Weaponry should be focused on weapons you'd use if you were to 1v1 an actual player using the bot, and should be focused on taking advantage of type.
You're fighting one bot of each type, regardless of difficulty, so every weakness will come into play. Just like in the C.S. boss fight, enemies will take 100% damage from all types, and 400% damage from the type they're weak to. Unlike in the C.S. boss fight however, C.S. is weak to melee instead of beam. I haven't confirmed Squidol Girl's weakness yet, but I do know that's not melee. Being that Toy is by far the most threatening of the moebots, having at least one melee powerhouse is quite useful.
However, Cyberstep doesn't want your lives to be easy, so you fight the bots in the order of Toy (art) -> Byne Girl (land) -> Aquila Girl (air) -> Everyone. This means if you start with a melee land, you'll be using a melee land against Byne Girl. And you can't open with an art against Aquila Girl unless you use one against Byne Girl. On top of that, due to the wildly varying terrain at the outposts and in the areas themselves, it's very likely that you'll be using an air. The easiest option is to take the deaths as they come, but for perfectionists, open with a Seraph, Aquila Girl, or Shaden using a slayer or dual pepen bit. When flight speed and your boost gauge aren't a concern, the missiles are quite avoidable on an air. You'll be able to start against Byne Girl with an air, making her a free kill. Aquila Girl can also be dispatched air-to-air with alpha builds and mini bazookas. As mentioned though, it's probably less hassle to just take deaths as a chance to switch types.
Fightan
Toybox Girl
The fight opens against the most threatening of the group. Toy-chan hits very hard, with superb homing, missile speed, and damage. She'll alternate between regular missiles and cruise missiles, and occasionally flying around a bit. If there's an attack pattern here I haven't seen it yet, just know that she's going to shoot missiles a lot. End this phase ASAP with melee, a Vanguard can solo her in mere seconds on 1*.
Byne Girl
Byne Girl is by far the easiest, but she also hits extremely hard. Obvious Byne armor aside, all she does is run around a lot before occasionally going in for a (very) high-damage punch with AoE. Be warned that she can chase you into the air with her punches too. Her cue for attack is when she starts running directly at you, either get out of the way or activate your wonderbit. Though the obvious strategy here is to heckle her with beam weapons from afar, due to her lazy fighting style you can actually get away with meleeing her too if you're cautious about it. If you're using a dual melee bit, her punches can be frequently taken by the bits as they attack in front of you, preventing you from even becoming a target in the first place. Note that after a point, she'll armor purge, allowing her to use a triple punch combo.
Take note that she always looks at the person she's going to try to punch before she starts running. As long as you keep an eye on who she's watching, the only reasons you should be hit are if you're an air that's out of boost, or if you're alpha striking and can't stop in time.
Aquila Girl
Aquila Girl is pretty annoying for several reasons. Her homing blaster does fairly decent damage with a fairly decent interval, and is obnoxious to consistently dodge. She'll spend almost the entire fight flying around, which can make her tricky to track. And, since she follows Byne Girl in the rotation, you're probably not opening against her with an art. Her attack pattern is incredibly basic; all she does is float around spamming her homing blaster. On 3* (and maybe 2*?) she starts using Full Boost once her health drops past a certain point, which makes her more annoying to hit by speeding her up considerably. There's not really a strategy here beyond "shoot her", she's just annoying.
This is a gimmick I've only tried once, but dropping a sniping unit on the edge of the platform the boss girls spawn on seems like it can both distract her, and stun her occasionally. It may have been just a fluke, but she didn't get up in the air and moving at all last time I fought her, dropping to the ground shortly after taking off.
EVERYONE
Aquila Girl, Byne Girl, Toybox Girl, C.S. (1* and 2* only), Squidol Girl (3* only)
That's right, everyone at once, with no nerfs involved. Better crowd control weapons and longer range weapons should be used here, but the same general strategies apply. I cannot stress this enough: take out Toybox Girl first. People will die left and right if they have to try to dodge around cruise missile spam while dealing with the other three girls. The support should be next to go. Take out the last two in whichever order. Because C.S. and Toybox Girl are both melee weak, using melee bots until both are eliminated is the best option.
On 3*, Squidol Girl replaces C.S. Squid's main forms of attack are spraying ink (basically a pre-nerf laser that causes disorder; stay out of range if at all possible) and spinning while flinging ink everywhere around her, which sits on the ground in puddles and causes slow. She can also tentacle whip you if you get too close; be very careful about this, it disables your subweapon and she can stunlock you with it if she wants to. All in all though, her damage output is low, and since she has no weaknesses you'll probably end up dealing with her last.
