So I defeated the Jade Oni and then it told me to go talk to the emperor, but I had to get off wizard 101 so I didn't. The next day when I logged on and tried to go talk to him, he wasn't there! I tried going out and back in but he's still gone. I follow my arrow and it leads to a spot where nobody is standing. The only person in the room that I can see is the Jade Champion by the door. What do I do??
You have to talk to the Emperor after you defeat Jade Oni and BEFORE you leave the room. If you leave the room, you're out of luck.
To fix it, you're going to have to defeat Jade Oni again. Talk to the Jade Champion and defeat the Jade Oni again. Then talk to the Emporer BEFORE you leave the room. You'll get the quest "The Key at Last" which will direct you to go see Professor Ambrose.
If you defeat the Jade Oni again and STILL can't find the Emperor, than your quest is bugged, and you'll need to send in a ticket to Support.