Du You didn't wish to create more Demonic Flame Skeletons; after all, the Soul Devouring Demon Flame on the skeletons was very effective against Dark Creatures, but even if Du You wanted to do so, there was no way he could.
Unless encountering some Magical Beasts or animals, Dark Creatures simply wouldn't leave behind any corpses.
Every Dark Creature killed would eventually disintegrate into chaotic dark forces and disappear. What remained was a skeleton. Yes, these Dark Creatures actually had skeletons within them.
It is known that true Element Creatures would not have any structures other than elements themselves. And yet these Dark Creatures, not only were their elements extremely chaotic, they also possessed skeletons.
If they didn't lack any trace of Undead Aura, and Du You hadn't confirmed they weren't Undead, it would be easy to mistake them for necrotic beings. These bones had been thoroughly infiltrated by powerful dark forces.
