The Dragon and Albeiro.
So i just noticed in chapter 103 page 10, (or the link below) that Albeiro tells Evangeline to come visit him after the tournament. Then when Evangeline asks him where he is staying he tells her "Negi and his cute friends know where im staying." This leads me to believe even more that he either is the dragon (by means of some kind of curse) or he is sealed behind the entrance the dragon is guarding.
http://www.geocities.com/enmosjob/negima.jpg - Image
You know that this topic has been discussed in one of the other threads right, and I think it was in the "where is Negi's father" -thread.
EDIT: I just spent a few minutes looking through the thread I mentioned and found the topic being raised there
(We ought to make a thread where already raised topics are listed so people don't post it again.)
Eh I stopped paying attention to the Where is Nagi thread a long time ago after it started getting filled with poor quality posts. Just thought it deserved its own topic considering its a pretty solid piece of storyline hinting towards a very important piece of storyline. It doesnt necessarily concern only Nagi, I was more interested in the truth about Asuna and whats beyond the skull on the map.
Well, if you can rename the topic to "the dragon under the library" then we'd have a broader topic.