Warded to Viktor
I have to admit that I'm not at all familiar with saving people from their sisters, however, I could try pretending to be Gryffindor for a bit? Or I can do what I do best in situations like that: offer the best refuge possible... or just ask you to come over, so I can indulge in you company for a bit.
What kind of party do you have in mind? A dinner party or something more festive? You know, Cho Chang is my best friend, and she does wonders with parties of any size.