A Decisive Battle.

Although Thufrat had a serious feeling that this lich was the same one that he and Ark had run into in the past, there was no real way for him to make sure unless it also recognised him. Although he wasn't very sure if his guess was correct, he still shared it with the others. If the lich was actually the same as the one they had run into in the past, then maybe this was a sign. An old enemy showing up exactly where they had lost Ark's trail, what were the odds of that? 

Once he shared the info with the others, their expressions became even more solemn, but their fighting spirit was also excited. Since they had pretty much confirmed that this lich had something to do with Ark's kidnapping. Now that they knew that they were fighting for Ark, they became more serious than they had been before. Initially, they were more inclined to at least retreat before confronting this lich, but now, that was no longer an option. They had to fight the lich, and they had to defeat him.