Merge in Liminal will show him what Sayf was shown: a yin-yang globe with two beings at work inside it, which we can thread or handwave.
As far as insight: he will realize that people are not "becoming" Harbingers - the consciousnesses behind the Starquakes are using Harbingers as extensions of their Will, with very little understanding of what they are doing.
Re: Council of Senpai, Double Valence-Era - Lupa