After Jiang Chen ascertained that Lin Tianjian wasn't chasing after him, he slowed down. He wasn't really afraid of fighting Lin Tianjian because, if worse came to worst, he could ask Lu Ping to come and help him. But he didn't really want to do this before the start of the banquet, and this was especially the case since he had already killed Wang Fei.
After the death of two Flame Emperor's inheritors, one after the other, the Fire God Ring wasn't as hot as before, and the Flame Emperor actually showed himself. This meant that the only Flame Emperor's inheritor left in the Divine Tree was Jiang Chen.