Implied is a matter of interpretation. I am not saying that my interpretation is a matter of proven fact, either, but without anything definitive to tie it to Mandrakk, it can't be used for his profile. I think there are plenty of issues with that interpretation.
Later CAS says "the inexorable (unstoppable) logic of a living story drives us towards it's conclusion." The end result is that both of them are destroyed. Mandrakk is consumed by the Overvoid and CAS is destroyed beyond repair. In my interpretation, what CAS meant by the "inexorable logic of a living story" is referring to his and Mandrakk's role as the "hero and villain" of the "story" and that their roles as hero and villain inevitably result of their mutual destruction, CAS' self sacrifice to save the world. Mandrakk's death was retconned by a later writer, but this isn't particularly relevant as to how we interpret Final Crisis.
It could be interpreted numerous ways, so I don't intend to entertain a debate about it, but the fact remains that we are never told what Hyperstory is, or what any of this means, so attributing it to Mandrakk is just as speculative as any other approach, and isn't satisfactory evidence for a character profile.