While using the full manifested form of his [Son of Luserus] skill, Skullius had a vast sensory range enabled by the fact that the skill itself improved the quality of how Luminant he was – if it could be postulated in that manner.
According to Luserus, the reason why the skill hadn't worked for Skullius before, was because he was diluted, with the cosmetic body he had combining aspects of his former Discount Human form and the proceeds from the Luminant Seed, which granted him the bodily qualities of a Luminant.
Of course, the one who made Luminants and the skill they used to ascend into beings made of light – Luserus – would be able to allow Skullius to use it without prerequisite, and as a result, the absolute control Skullius felt from the surrounding mana increased significantly.
As a result, the Hybrid Luman had been able to sense finely how Ashema's ability to incarnate into other vessels worked.