At first, the Seventh Slayer had fought Ye Futian at the underground palace, but he had been defeated and thus no longer had a chance to compete for the spear there.
Later, they worked together at the Spatial Sacred Hall, where he had made a surprise attack on a Renhuang from the Martial Gods Clan's alliance. He had been wounded then but had chosen a divine arm that had helped him reach the Renhuang plane. Although there was not the least bit of friendship between him and Ye Futian, he had had some modest success on this trip to the God's Relic, and his previous defeat at Ye Futian's hands had not been too hard on him, and Ye Futian had not been cruel to him when he was wounded.
As far as the Seventh Slayer was concerned, he had received Ye Futian's favor. Now that Lian Jiuyou was attacking Ye Futian, he would act in order to repay him.