They never even meet in LOCH and never speak to each other in ROCH. At the 2nd Hua Shan, after converting Qiu Qianren, Yi Deng just leaves even though Hong Qigong asks him to wait until Huang Yaoshi shows up. In ROCH, even though they spend a considerable amount of time together at the end of the book, they never say so much as a word to each other. Makes me wonder if they didn't really get along.