Chaos core.
Of course, it was something Northern had never heard about or thought existed. He didn't think he would ever come across a rift whose core was crafted using explicit properties of Chaos instead of soul.
Northern stood there with gleaming blue eyes as he pondered a few things before proceeding with what he was supposed to do.
'But if it's a Chaos rift, why were they enemies that function only on the principles of soul essence? Or in this case, should it be Soul force?'
Northern paused, his arms folded while thoughts seemed to pound his own head.
'No, things that I have no idea of are popping up. All the more reason to go to the academy and find out whatever I can about all of these...'
The academy was an atheneum with all kinds of books, and most especially, detailed records of the history of both the world and the rifts that several Nations and clans may have missed or do not have.