Quote Originally Posted by Sidnne
No, "Shadow" itself is not a traditional element, per say. But, in the ninja world it would have to fall under some type of affinity, if not a combination of two, like many others.

You also forget that Kishi just introduced the elements a few chapters ago, and is basically pulling this stuff out of his ass as he goes.

Kankurou is a Jounin, but we have only seen him use puppets. Are puppets an element? We have only seen Temari use wind so far, and Neji... who knows what element Byakuugan is using, but we haven't seen two from him either.

Kishi is making this stuff up, and at times contradicting himself. So don't be surprised if he decides that Shadow is a combination of two elements, just for the purpose of promoting Shika.
If jounin level ninjas require at least 2 elements, then how could Gai be a jounin? Also, Rock Lee is completely screwed since he can't use ninjutsu at all. There is definitely a an overall basis for making shadow a "hidden" or "secret" elemental affinity since Itachi used it way back. Or it could be a combination of two basic elements like wood or ice. Or it could be a bloodline limit, who knows?

I think Kishi was thinking of this stuff ahead of time though. If you look back even to the earliest parts of the manga, Kishi was using the elemental circle in fights. Sasuke's blazing fireball didn't have any effect on Haku's ice jutsu. Kakashi used an earth jutsu (Tracking dogs) against Zabuza (who only used water jutsus). It's also heavily present during the Third's fight with Oro - Third uses Fireball; Second counters with water wall; third counters with earth wall.