Kaze

If you're having trouble with Cynthia attacking Sumia, try flying her in Cynthia's attack range unarmed and preferably doubled up with Chrom and see if that works......as long as Sumia is at a high enough level to not take too much damage from her.

Wow, I just did that chapter not too long ago. I managed to do it the first time, but Fred got knocked out trying to protect Sumia from the archers (damn you 30% hit rate that always seems to hit!). She managed to somehow dance her way out of that arrow storm, I will never know how, and eventually Cynthia herself moved closer to attack so I could finally reach her. Wasn't too hard if you wait I guess...

Hmm. I'll have to test either strategy and see if they work. I was close to getting Cynthia, but for some odd reason Sumia decided she would be useful for once and kill her. >.<