This is my strength

The middle aged man didn't say anything at first as if he wasn't about to answer this question, but there was something that happened as he stood there.

There was this blood mist that appeared in the area around them.

Before this blood mist appeared, Lin Fan had no idea that it was even there.

But after it became thicker and thicker, Lin Fan suddenly had an idea of what had happened.

This blood miss most likely had been in the area around them the entire time, it was just that he didn't notice it at all. It was only when the middle aged man made it thicker that he was able to notice it.

With the blood mist in the air, Lin Fan could guess what the middle aged man used to detect him.

The blood mist must be some kind of special sensor that allowed the middle aged man to sense him even though Lin Fan had been using the illusion spell. He didn't know what the blood mist showed the middle aged man, but it was a fact that he was able to find him.