Ever since Skullius had felt the sensation of a deathly grip that had wrapped around his <HEART > back during his fight with Bassbion, his flesh had never felt the same.
Even without wielding Demion's Dance, he felt the coil that promised death whenever he was using the [Swindling Death's Death]. Each one of his strikes couldn't be lacklustre, otherwise he could suffer dreadful consequences.
When his body was reforged with Luminant Seed, it seemed that this deathly energy that manifested as a dark red, borderline black ooze which leaked from the green sword, was now a part of him, tainting his flesh and bone.
This was something that primarily came with the [Swindling Death's Dance] technique.
The <CURSED HEART> and <CURSED BLOOD> were products of this and ultimately, without even holding Demion's Dance and even with [Swindling Death's Dance] being incomplete, Skullius could wield this pure death energy to a limited degree.