I think Aiden's return might cause Ciara to have another excuse to act out. Hence why I speculate Ciara might dig her claws into Chad or at least attempt too. Sometimes when a guy is treating you just right and helping you out rely on can change how a person feels, especially if the person was abused by a man.
I am seeing early similarities of a "connection" with Chad and Ciara that we saw with EJ and Abby over Jack's book, until that led into a affair. I feel the writers are going down this path, however, let's hope Chad don't give in like EJ. Again this is my speculation, not fact. Regardless, Aiden's return will start a wave of twisted confusing events/scenarios on Days.