Julietta

Julietta is a witch that appears in Magia Britannia. She is the witch form of Elissa Holmes.

Witch
The Witch of Intelligence with a reserved nature. She is bursting with knowledge, and knows of everything and anything that exists within this universe, save for those she deems "unnecessary." With her heart hidden away, she cannot show her true emotions and often has blatant disregard for those around her. No one will ever believe it, but deep down, she truly does care.

Yale
Minions of the Witch of Intelligence. Their duty is to be key keepers. The keys are said to unlock certain rooms that contain information the Witch has rejected; memories she desperately wishes to keep hidden away. These vigilant Familiars are extremely protective of these keys and become hostile if they feel they are in jeopardy.

Trivia

 * Yale is a reference to Linus Yale Sr., inventor of the modern lock.
 * Julietta's "halo" is a model of a uranium-235 atom.