((I don't really like the idea of just scrubbing out someone's ideas so....How about: This 'guardian' is only part of the entity, representing one aspect of the guardian's full power. However at this point since only one piece is found it can't really do much other than guide us to the other pieces. (We can't really summon THE GUARDIAN until we get thew rest of the pieces together)
Maybe that one Cassie has is a evil spirit pretending to be the guardian. We're being lied to again!!!(I hate being lied to)
Maybe it's the guardian spirit's wimply little brother trying to prove itself in his bigger brother's abscence. (Wha???)
Don't quote me on any of this, it's just off the top of my head!))
