Yuan Fang, Zhao Sheng and one unknown. While not being a part of eight freaks Sima Yi learn the rain God tactics from Yu Ji, while Hua Tuo learn all the medical techniques from Yu Ji as well. The final one is probably Zhang Lu because he is the current lord of Hanzhong and the Lord Preceptor of Five Pecks of Rice.5? 3 Zhang brothers, Yue jin, and Zuoci? And who are the other 3?
It looks to me like Xun Yu saw the 8th genius back when he talked with Sima Yi because their words were the same, and the theory about the replacement of Sima Yi by Zhao Sheng aka the 8th looks the most reasonable to me for nowSecret code.... so, is Sima Yi's words when speaking to Xun Yu supposed to be a message from The Eight/Zhao Sheng? Or is it something he planted somehow? Hmm, I don't know how the latter can work exactly, but I have heard that the reason Cheng Pu manage to not get hypnotized back when Sun Ce is alive is because he's just too smart, so I won't put it pass this series.