Jacob was back in the Timeless City, but he wasn't in the Infinite Space anymore for obvious reasons.
After Nyx alerted him about the Star Auction Virtual House and the Yang Flame, he had to come out. The reason for his reaction wasn't that he wanted the 'data', after all, he already had the Map of the Blazing Constellation. He wanted it to make sure others wouldn't get in his way or ruin his plans.
After all, if that data turned out to be really leading towards the Yang Flame, Jacob would be forced to take action.
Although he was sure that the Map of the Blazing Constellation might be some kind of key or the only way towards the Yang Flame, he couldn't take a risk or overlook this. In fact, he almost did, but Nyx alerted him in time.
Now, Nyx was participating in what was presumably the most significant auction of the Legendary Plains, and Jacob had to admit there was some merit to it, since the Yang Flame hadn't even appeared yet; some items had already piqued his interest.
