Ah, I see
. Hmm, now that I think about it, back then I haven't commented yet...
The biggest challenge in writing a Negima-Nanoha crossover (or a Negima-any anime title, really) is that Negima is yet to be completed, and the developments are sometimes extreme enough to throw any crossover into whack.
And I don't know why, but some fics makes their crossover with post-A's Nanoha and
post-ending Negima, making it very susceptible to any new revelations or character developments. In my opinion
Equal and Opposite Attraction is one that falls victim to this, with the characters acting as if they haven't change from the beginning of Negima
(and then there's the matter of the calm, listen-to-both-sides-before-commenting Lindy going into an outburst after learning that Negi has fought from a young age, nevermind that half her best combatants are ridiculously young as well). A Negima-Nanoha crossover would be better if both start at the beginning, or relatively beginning.
Not that a crossover
can't be done. In fact there's some interesting concepts that can be used, like the Bureau helping the
*spoiler*recovery of Mundus Magicus/Mars*spoiler*. Not to mention Negima has its own interesting brand of magitech.