B for Medea, G for Aria. Medea knows herself best so it's fair for her to just have larger than normal effects, and meanwhile Aria can watch the border between reality and fiction blur a little.
As for questions (not necessarily attached to any one person):
- What exactly does it mean to be a 'coven'?
- How do magic oaths work, and do they differ between Medea and normal people?
- How has magic kept itself hidden from wider society?
- Who else supernatural does Medea know? How many vampires/witches/alchemists *are* there?