I was thinking about Sylas' plan and like, he knows there's going to be a power vacuum once the leadership topples and the second it does, Noxus is going to take advantage of the chaos and try and take Demacia.
Sylas might have a chance at toppling the Demacian throne because the Demacian army is unwilling to risk civilian casualties or use magic to counter the rebellion, and he knows that, he's banking on it. Noxus though? They have entire trained mage units and do not care if civilians are in their way. If Sylas topples Demacia, I give them roughly a week of chaos before Noxus takes the whole kingdom.