The day we find that dragon, the melders will have roflestomped half of Illyriad, King Siguard's poltergeist uncle will have left his volcano island, the council of five will have split the world in two and it will start raining arterium.
Ow.
In any case the magic that protects them protects them by keeping them hidden. It's passive protection, something we couldn't destroy the HoC with.
On the other hand;
"Archmage Stendas, a Human believed to hail from the Windseekers, commands even the vast oceans." ~ Council of Five.
How did he get that power? Friendly Dragon hunt time! Where would you be if you were an ancient dragon? In any case, there's not a lot of information to go by. So we'll have to wait till the Devs quietly slip in some morsel of information that leads to Illyriad's largest treasure hunt.
Soon... Soon...