Caribou?

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When Twilight gets Fluttershy back, she will want a master. Plus, if the demon goes too far, twilight might be strong enough to turn the tables on her by that point.

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2 Always stoked to see this update.

3 - Sweet Apple Acree, and when she can't live with the happy honest family, their overworking, the apples at every meal and rising at morning, and is desperate offer her another place by changing a little the deal

“Then how about having a night a week with Rarity, me or any of my other friends that are willing as payment for your cooperation. We are heroines and I am a princess, so laying with either of us high value ponies would not be something you could get by easily.”.

Is that including Spike, Gallus, and Big Mac as well?

1. Twilight’s Castle

1. Twilights Castle.

Could have rooms set aside for Service, Interrogation, Debauchery and Greed amongst others?

4 imagine las posibilidades

1. Twilight's Castle.

This way we can keep a close watch on her and pick her brain for information.

I say Twilight's castle. Not only will it help keep an eye on Cereph but it is also big enough for her to keep a pleasure dungeon to satisfy her need but also soundproof enough for her "victims " to howl with pleasure and not arouse the suspicions

Heresy quick someone get the grey knights!

*pulls Bolter receiver*
For the emperor!

I say 1.

6 She & Mayor could work together and even help each other out with some urges. Mayor future pet?

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1 - the Castle
While a part of me is curious what living with this demon would do to Rarity, the castle is just the better choice. Guards in case Ceraph does something, or someone tries to do something to Ceraph. Plenty of room, sends a flattering message to Ceraph of the benefits to cooperation. And reinforces the message to the public that she is an ally.
Will probably make ponies more sexually corrupted as the see their leader invite a lusty demon into her castle, but that is the type of story this is.

4. Could be interesting having her with the Cakes.

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2. She's already there anyway.

1 Twilight's castle

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Option 2 ( two ).

I'll go with option 2. She and Rarity are already acquainted, and what better way to show mutual trust then shortening the leash, so to speak.

Twilights Castle the place is big enough for a small army so Twilight can make room for Our sexy succubus Girl.

Oh are we going to see the results of leaving Spike to watch over the potions when she gets back? I would love to see more spike transformations.