Yea, I'm pretty sure they used some kind of nifty 1337 hackerz power to save the World... didn't they say that Aura had also given Rena some kind of power too? One that could only work in conjunction with the bracelet?
Shugo: RENA!
Rena: ONI-CHAN!
Shugo + Rena: WONDER TWIN POWERS ACTIVATE!
Anyway, it's not canon, so I just think of the anime as a drug induced dream, like Willy Wonka and the Chocolate Factory :p
