I think..
Remember, Lyle made it to Aridia because there was ONE WAY to Aridia.. Right through those fortresses. It wasn't a private knowledge things.
Then Lyle stole the item from the cyborgs to enter Landen.
You can also go Landen to Elysium without a gem I think then Elysium to somewhere else..
It could be that Lyle learned how to fix his world and he needed a pure blooded descendant of Orakio and set Maia up to be found and then kidnapped her to send Rhys on his way..
This all coulda been orchestrated by the Sages in Lashute.
We also should take into account that Siren has no personality and no emotions. He just follows his programming. Laia sent Siren away and the Layans are his enemy.
Someone finish Jap ps 3 translation

So much info left in japanese ps 3 x.x It wraps it all up I was told.