C573 Unforgettable Memory

I asked in the same ice-cold voice, "Who are you?"

The cold voice spoke again, "Hehe, it doesn't matter who I am. The important thing is that you gave me an unforgettable memory. It's time for me to return the favor. "

My mind was racing as I searched my mind for any possible characters. But after searching for a long time, I couldn't find anyone. I didn't even find the slightest clue