I went into Byakuren in that run with either 3 or 4 lives, and made it to her last spell with 1. (darn it last spell) On practice I'm worse, because I usually use up ALL of my lives, somehow. >_>
Don't ask how, I don't know. :ohdear:
But yeah, I've practiced her many times over, and she's a royal pain every time, mostly from that last spell card and curvy lasers. I can't read those!