When Mutran met Tren Krom, Tren Krom read the Makuta's mind and Mutran was able to read Tren Krom's to some extend, thus learning that Mata Nui could actually be harmed. What exactly did Mutran learn, though?
Merely that Mata Nui had vital systems somewhere in the Matoran Universe which could be used to harm/influence him?
Or the complete truth - that the Matoran Universe was in fact inside a giant robot and how that robot worked?
Or something in between?