'Ahh, now I get it. So, these women were lured here by that bastard Li Lei, and fell into his trap. When they wake up, they wouldn't remember anything. And this Formation was invented by a traveling Taoist during the Southern Song dynasty. I had a chat with him back when I was in hell. I learned some interesting stuff from him...'
However, despite this Formation's power, once you fall into it once, you develop resistance and it no longer affects you.
Also, the Formation can be set in two ways, it's effective either only on women or only on men.
This Formation in front of us, is of course, set only to be effective on women.
So Wu Shanshan fell into the trap, while Huang Xiaolong was completely unaffected.
Actually, this Formation and various other Formations all harness the subtle energy of Feng Shui, influencing and stimulating the brain. Feng Shui, just like the waves in the sky, it's always there whether you're an ape or a great man, no matter whether you believe it or not.