Aeon is in an Enemy Mine with Galamoth.Word of God has recently stated in a Q&A session that Galamoth has already played a role in events in the story, and also that part of Aeon's mission is to avert the destruction of the Castlevania timeline by returning the Castle to its own universe. Now, something like that seems like enough of a Godzilla Threshold for him to be willing to work with Galamoth who, as we know from Castlevania Judgment, is a rival of Dracula's. So, it's reasonable that he's got enough motivation to convince Aeon to work with him.
- Jossed. It turns out that Galamoth was the one who tricked Aeon into scattering Dracula's remains in the first place, in an attempt to steal Dracula's position, which got Galamoth destroyed by the Castle.
The Castle wants to corrupt Twilight.The reason why the castle is targeting Twilight is because somehow it learned about her history and personality and it realized the similarities between Mathias Cronqvist and Twilight:
- They both are intelligent scholars who specialize in magic
- They both can plan (case in point how Twilight dealt with Actrise and how Mathias became Dracula in the first place)
- They both have a close relationship with their local god.
- Twilight at the end of book 1 is starting to show doubts about Celestia and Luna.(Remember Dracula's start of darkness?) Perhaps later, she'll call them out for hiding in their cozy castle drinking tea while she and the rest of Equestria suffered, and lose faith in them. Or one of her friends will die and blame them for not doing anything. The castle senses this and either plans to use Twilight as a vessel for Dracula or turn her into Pony Dracula. Twilight has spent long periods of time next to Dracula's rib and she has been getting irritable and more controlling lately (in book one she makes a mental note to strangle Rainbow Dash when she asks her about Shining Armor; she was going to lecture Spike about obedience over a misunderstanding). Noticeably after giving the rib to Actrise, she did get more cheerful, right up until she saw the corpses. Perhaps she'll obsess over stopping Dracula and get too close to Dracula's corpse and get possessed. Remember what happened to Maxim? Or Dracula's spirit is already partly inside her head and he'll try to manipulate her into reviving him and/or turn her evil.