No hate against the artist or anything, but it'd be unfair for everyone else who participated if someone who actually broke the rules won because NCsoft wasn't aware of this issue. Enna Mae sorry but no. Blatantly copying someone's work and tweaking a few minor things is never acceptable and I'm sorry for you that you feel it is okay. And it's kind of hard to make an outfit not look like some outfit from a game or anime when there's loads of them. Blade and Soul Gold You can't really make anything "original" without some aspect of it being copied from something else, even if that wasn't the artists' intention.
And it's not even like they're tragically unaware of the issue, they blatantly don't care as exemplified by the fact they had a runner up whose artwork was completely stolen and they didn't bother to check beforehand. This means that they don't particularly care to check the integrity of the artwork, which is a huge slap in the face for those who have come up with original designs and have tried really hard.
There is also a distinct difference between imitation and inspiration. If that mask was inspired, there would be more changes than just the color Cheap Blade and Soul Gold and one extra notch in the top part. But the mask is, I would say, at least 75% similar to the Fire Emblem mask, and by that point in time should be considered plagiarism.The lyn costume looks like Elin Reaper costumes from Tera tbh.
Tracing poses or using them as a reference is not theft of an IP. Especially if it's merely concept art and not necessarily promotional and considering most of the pose references and tracing comes from BnS concept art. Definitely no. It could be considered plagiarism tho'.
That mask however... That.... mask....