Nah, Sera wouldn't want Ceci as her slave, Sera is a better person than that, she now has her hubby and is in the path to happiness, she doesn't care about revenge anymore.
But I am crazy to see when the new Ceci scenes come if something like this will happen:
-Ceci enters the room, looks at Sera's on Mars arms and say "What are you doing there Sera? Did you forget your place? Your mistress need a foot cleaning, get on the ground"
-Sera makes a sad face, starts getting up, but Mars stops her and say: "Sera is my wife now, if you want to keep this roleplay she will be the mistress"
I just want to see what kind of expression Ceci would make in this situation, losing control is what she hates the most