Ironically, after playing said "worst spell card ever" like 10 times after all this, I've suddenly fallen in love and I think it's an amazing spell card (didn't manage to capture it though)
Kogasa's first is evil, but I'm seeing that it's micromemorizable. The problem is just what IS this path to take? I've gotten within five seconds of capturing it though.
And her second is surprisingly easy. It rarely walls you and as long as you have your wits about you you can just micrododge in the center and end it in about 15 seconds.
EDIT: Also I just realized: Nue has broken the extra boss tradition of having her portrait in her spell card background! UNFORGIVABLE.
Well Ran didn't have her portrait either D:
Also for Kogasa's first card, it's much easier if you're using any of the A-characters, since their shots all go in front of you. What I do with MarisaA:
-When Kogasa starts the card, she summons four parasol bullets. Destroy all of them and move to the right.
-She should move in front of you. At this point just follow her location and shoot the parasols that get in your way, don't bother with anything else.
I find it easier to dodge the large blue bullets than the parasols, but maybe that's just me.