Judging by the crack, this was likely left inside the Spirit Pearl unintentionally during a clash between a Demon Cultivator and an Orthodox Cultivator.
Because it was so well-hidden, it wasn't discovered afterward, eventually making its way to Xianghe Market.
He would have to find the source of this blood-red mist to figure out what it truly was.
'It probably won't be easy to find. I'll have to take my time.'
Xiao Chen considered it. Since he hadn't received any related warnings, this technique had probably gone unnoticed by the allies on the front lines.
From this, he could deduce that it was likely an underdeveloped technique of the Divine Fire Sect, probably only used on a small scale in a specific region.
It might even be a personal technique obtained by a single Demon Cultivator.
Otherwise, a weapon this devastating would have caused a huge stir and become common knowledge by now.
In that case, tracing its source would be no simple matter.
