This forum apparently has many threads about
Kurohime the manga. However, I am surprised noone had posted this animated intro until now.
As you can see, there is an AP transformation sequence for Kurohime in this animated intro. Sadly, due to the low quality of this clip, it's hard to notice the process. I couldn't find any other version of this clip with higher quality yet, but it would surely be nice if we can find one.
Regarding that such animated intro exists, it looks like the series was going to be animated due to its fame in the past. (You can also find an intro for PS2game of Kurohime on Youtube O_O) However, the animation project seems to have been canceled from what I've read about it online. If this is true, then it's really a shame since the series features many AP/AR sequences for numerous characters in it. (Kurohime, blood-sucking girl, snow girl, and more) We really need an anime like that...