Bullet Hell Artistry #3 - Middy
For this contest I'm using a 25 point rating scale so I don't get fined.
 
Danmaku Quality: 15/25
 
Danmaku Quality encompasses the quality of the danmaku in your script. "Good" patterns will equal a "good" score in this category. What makes a pattern good is subjective, but the #1 factor is fun. A flashy, gorgeous pattern that isn't fun won't fare well here. Note that aesthetic factors can still factor into this - proper usage of sound effects and graphics can make an unfair pattern fair, and improper usage of those can make an otherwise-fair pattern unfair.

To be more clear, an "average" pattern is a 5. You can gain or lose points and I'll probably tell you why.
 
Individual patterns will be rated out of 10. The average of that will be taken and scaled to calculate the Danmaku Quality score.
 
Aesthetics: 5/25
 
This category encompasses how your entry looks (and sounds). While danmaku should absolutely come first, visual and audio elements are also a part of the gameplay experience.
 
Final Boss-ness: 5/25
 
5 points will be dedicated to how well the character feels transformed into a final boss. It's a judgment of how their themes translate into a more "serious" fight. Mostly subjective, but I'll try to give detail about why I rated something highly/lowly in this category. 
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Nonspell 1: A good variant on Mystia's usual. Doesn't last very long for a "final boss" 6.75/10.

Spell 1: Fairly fun, just not super interesting. 6.75/10.

Nonspell 2: A decent test of your reading ability. Also pretty short, but I like this more than the previous non. 7/10.

Spell 2: The evil eye thingies in the darkness look pretty cool! The pattern just ends up being run-of-the-mill dodging though. 6.75/10.

Spell 3: Flickering bullets are something I haven't actually seen TOO often - I think it's quite appropriate for Mystia. The pattern isn't super interesting but with a gimmick like that it simply can't be. Not that this is bad, though - I think it's pretty decent. 7/10.

Spell 4: Another interesting gimmick. The dodging is kind of generic, but the gimmick makes the spell more appealing. 7/10.

Spell 5: A multi-phase script ender, it seems. The darkness does make reading it a little harder, but otherwise it's fairly typical Mystia. 6.75/10.

Spell 6: But wait, there's more! I think this pattern's pretty odd, because the first phase is the hardest phase AND the most interesting to dodge in my opinion. Otherwise it's fine as usual. 6.5/10.

Danmaku Score: 6.8125/10 (scaled to 10.22/15)
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Aesthetically, I'd say this script is very cohesive. I think it's weird how the player shots obscure the boss sprite when the feathers are disappearing - not a problem gameplay-wise, but it's unfortunate that your spritework gets covered like that. 3.5/5.
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I think this script's final boss-ness is about average. On one hand, the nons and early spells die SUPER fast - maybe there's a balancing issue there? On the other hand, multiple multi-phase attacks and a survival kind of make up for them.  2.5/5
 
OVERALL SCORE 10.22 + 3.5 + 2.5 = 16.22/25