Also I approve of Tomoe, we need more japanese peps!
You could even push up her End to B if you want, we have some very-high-stat Servants running around here with double A's (and I even think a few tripple A's....god what were people thinking)
I am thinking the same as fish though, a A-Rank Anti-Unit NP is fine, but given that it is A-Rank and the description just made me consider for a moment it would be some auto-hitting thing since it sounds so 'simple' in itself, if her anti-army thing is just a random gust of wind that only blows people from their legs you could even drop it to E or D Rank I suppose.
What am I saying is, while RP is more important than stats and alike you could improve her power, seeing how you only watched Fate/Stay Night you might have been unsure on what to do, you don't need to. As I said people could help you and while your character is most likely accepted from nearly everyone already I just wanted to tell you that.
E: Also you could always join http://us12.chatzy.com/58949003725428 Fish of Oblivion and me are online there most of the time, but other people are active there aswell.