The elves wanted to help Zhang Yi, but with all the humans including the Sword Sect Divine Realm elders leaving they saw no sense in risking their lives, if the three great elf sects came together they could get hundreds of elders in Divine Realm and some in the Eternal Realm and could attack the organization.
But only the elves would fight and it was very risky that many important elves would die in this war just to improve their friendship with Zhang Yi if at least the humans wanted to continue helping they could try.
Zhang Yi had no way of knowing that he almost got more help from the elves and thanked everyone who helped, Zhang Yi was really disgusted with this situation, he thought that the ideal was for the great sects to gather all the elders of the Divine Realm that they could and every one the elders of the Eternal Realm and thus attack the organization of soul eaters.
