C431
Since Yu Huo sent the order, he must be a fifth level Martial Disciple from the Divine Fire Sect. He was once again provoked by the other great sects and couldn't take it anymore and sent the order to him.
As for the summoning of an Emperor level powerhouse, Lin Hu had to go. The reason for that was because the message had the word 'please'. In other words, it was akin to him owing a favour