The old man was taken aback by what William said. He never thought such a kid would be familiar or all knowing about tracking marks left by high end spirit masters.
"Don't put it on me," William put an honest expression on his face, "my master always warned me from dealing with creepy old men. And she once promised that if anytime I met with anyone who used such cheap methods on me, then she'll go all out and teach such a spirit master a good lesson."
"..."
The old man's corner of eyes twitched, before he finally waved his arm as he used his spirit power, "it's gone! Are you satisfied now?"
"Hehehehe," William laughed while rubbing his nasal bridge in an irritating way.
"Dammit! You are a hellish monster, not a kid! Who raised you to be like this?"
"My master, do you want to say anything wrong about her? I'll relay all the words coming out from your mouth by the letter, I promise."
William raised his right arm in the air, as if he was taking an oath or something.