It says in the cast list that both parts (N'Kara and Ildico) were played by Simmone Mackinnon... but I didn't think they looked that much alike! o.o Also, why were they (apparently) identical? They were not related in any way... it's just not plausible...
In the movie, the 2 women looks similar but are not exactly alike. Flavius Aetius in the movie comes up with the sceme that he'll make Ildico look more and more like N'Kara so she can get close enough to Attila and then kill him. All you need to do is find someone with similar features to N'Kara and change her hair color and style and use a little make-up and it's not that hard to make Ildico looks like N'Kara.
Ildico's eyebrows were thinner and she used makeup, also she had no scar on her forehead. I thought it was awesome how she looked so similar and yet like a different person, great acting really, to play two different people in the same movie. Like Leo DiCaprio in The Man in the Iron Mask and a realllly good one, Micheal Shanks in Lifeboat episode of Stargate SG-1 where he switches about seven characters in one hour, some in the same scene.
I wonder how did they come up with the name N'Kara in the frist place. Attila's first (and favourite) wife's name was Arikan in Turkish and Réka in Hungarian. None of them resembles N'Kara...