Based on the Ghost Infants' previous behavior, they seemed to be immune to Spells, but Lu Sangjiu, with her Immortal Demon Attraction, had drawn her own conclusions.
First, she could sense that the Ghost Infants had previously been tinged with the aura of that disc-like Magic Treasure.
But now, perhaps because Lu Sangjiu had seized the treasure, or perhaps because the disc had lost all its power, the connection between them had been severed.
The only reason these Ghost Infants could surge forth again was because of the flute's melody; they no longer carried that strange aura from before.
Under these circumstances, she figured they might no longer be immune to Spell attacks. It was only natural, then, to test this theory with Immortal Demon Attraction—a technique that was both powerful and relatively easy to cast.
Even if it couldn't harm them, the resulting shockwave would be enough to hinder them for a moment, giving Lu Sangjiu time to react.
