You're the one who you said you were looking for a fight with Oboi. 

你才是你说的要找鳌拜打架的人。

这句话中的最后一个 you 是不是应该省略掉呢？

【答】你的理解是对的，应该去掉you。在定语从句who you said were looking for a fight with Oboi中，you said是插入语，去掉插入语后：who were looking for a fight with Oboi。who才是定语从句中的主语。