OK, Oz is just a kid, and he's clearly not ordering Kai to do his bidding. However, that doesn't mean he's not being molded to lead the cult or being used as inspiration for its followers. Remember, the first time Winter meets Oz, she asks him which one of his mother's carried him and who his father is. These pointed questions allude to the idea that Oz may be Kai's son, via sperm donation (hey, he is a Mensa member, which would make him a viable candidate).
Then there's his name: Ozymandias, from the poem written by Percy Bysshe Shelley. A key line in the poem reads, "My name is Ozymandias, King of Kings; Look on my Works, ye Mighty, and despair!" It's the perfect name for a future god of chaos, and the members of the cult — including Winter, Harrison, and Meadow — treat little Oz as if he has a special role to play in their plan.
