Originally Posted by Kaioo
Reshiram and Zekrom are Ying and Yang. Good and Evil. Light and Dark.
Not to throw water on your bonfire but that's what they are. That isn't to say your theories might be untrue, it's just Resh and Zek are intentionally meant to represent Good and Evil. The Ying and Yang of someone's soul.
Groudon and Kyogre represent land and sea, as well as sun an rain so it could be both. Those two are part of the 'weather trio' (with Rayquaza), so maybe the representation changes when they're part of a trio. Of course, Kyuremu could be the middle ground, a 'grey area' too.