The sickle was made of the devilish energy from the armor the old man was wearing. He wasn't a devil, so the devilish energy he helped create wasn't pure, meaning the sickle that appeared wasn't perfect. However, the illusion that came out from his brow was part of a real devil soul. With this devil soul, even normal metal could be turned into a devil blade, much less this sickle created from devilish energy.
After the devil soul fused with the sickle, it turned into a devilish sickle! It now also carried the dao of the devil with it!
No one knew which was stronger between Ling Tianhou's sword energy and the devilish sickle with the devil soul.
There was a flash of sword energy as Ling Tianhou's sword energy flew out from Wang Lin's finger. This sword energy was simply too powerful! Just it appearing caused the sky to change color!