For the
hp_fridayfive.
1."Batshit" Bellatrix LeStrange vs. Narcissa "Not a Sissy" Malfoy
In an all out fight? Narcissa - because Bellatrix would lose her head and Narcissa would be able to take advantage of that.
2. Remus "Moony" Lupin vs. Fenrir "Will Eat Your Children" Greyback
Fenrir, because he's more comfortable with fighting.
3. Gilderoy "Blonde Ambition" Lockhart vs Ludo "The Wasp" Bagman
Ludo. We're never actually given any indication that he's bad at magic. Just at several other things.
4. Severus "Don't Call me Snivellus" Snape vs "Seriously" Sirius Black
Erg. ><;;; This one I think would come down to the circumstances around it. They're frighteningly similar at times and seem fairly evenly matched in power. My bet's on Snape though because he doesn't have to worry about not using the dark arts.
5. Neville "Stubefy" Longbottom vs Peter "Pathetically Pitiful" Pettigrew
Peter. Because nearly anyone who insults him or hurts him winds up dead. I can respect that.