So, after beating syrcus tower and watching the final cutscene, it' s obvious to me who the bosses are going to be in ct3: Unei, Doga, Nero, Cloud of darkness.
Now that we know cloud of darkness is from the void and entered a pact with xande to allow the voidsent to invade, it makes sense why there were so many voidsent enemies in labyrinth of the ancients. As for the dragon enemies, they are probably being controlled by allagan technology.