@vcnomnom
@danich182
The message feature works as such: A level 10 tower may send and receive messages with any conquered tower. Any conquered tower that is NOT level 10 may only send and receive messages from a level 10 tower.
In other words: he can talk to them, they can talk to him, but they can't talk to each other until they reach level 10.
I should also note that the way every tower levels up should be different -.- the first few levels of his tower were based on simple things like bringing in items from the outside, making summoning circles, etc. However, the world tree and the castle were exclusives to his tower. Plus, all of his later levels (5+ I'd guess) involve the tower's affinity with Eris, Jamil, and Spica. Considering that Asura was the one who erected the towers, I highly doubt that EVERY tower is governed by the three celestial maidens.