Crystal barrier is quite literally a bodily function, I'd probably need proof for it being copied. (And even then, Crystal will just toss all her weaponry that bypasses those shields, such as her Nuke Launcher, as a worst case scenario.) Copying projectiles is fair (Though copying explosions wouldn't help her much, since Blood Veins means Crystal won't take much damage from explosions, and she certainly can't mimic that, and many other techniques get reflected or destroyed).
As I said, Crystal is much, much better against her own danmaku than you'd think. Hell, she's better against danmaku better than her danmaku. A less skilled enemy trying to return the favor against her Euphoria senses + Laser Brain + various passive mutations more akin to Frog Girl, but with no visible effect, (All of Renamon's projectiles would move slower and be less powerful, alongside other minute effects).
Not to mention, Crystal's AP with her strongest weapons is actually equal/above Renamon, such as with The Nuke Launcher, or better yet, plasma.
Smart Gun doesn't do an absurd amount of damage compared to, say, The Nuke Launcher, but is ungodly accurate and automatically targets nearby enemies.
Poison Gas is... mildly dangerous, seeing as poison gas exists in Nuclear Throne and can hurt her despite being a walking crystal. But she can also swipe away that gas with melee weapons. So, dunno how that would to be honest.
Lastly, Stress. Let's say Renamon can copy shielding as a defensive measure, though that's the only Mutation that provides anything visual to copy, ignoring the guns themselves. Stress is a gamechanger: as Crystal gets more hurt, she'll begin amping her reaction and firing speeds, up to about x2. Once she gets here, Renamon will find it even harder than before to land a hit: even in melee, she'll respond with incredible speed with various melee weapons, and at a range, she'll overwhelm Renamon with an absurd number of projectiles that Renamon can't keep up with, alongside explosions she can't shield.
Overall, just making things clear here. I'll vote Crystal FRA- It is very far from a stomp, due to AP + Teleportation + loots of attack mimicry, though Crystal does have large advantages with her Stress, skill, experience, and knowledge of her own abilities, alongside other small passives (Scary Face, Laser Brain, Euphoria) that'll tilt it into her favor. I'd say around 6.5-7/10 times, Crystal would take it.
