Teddie works in a similar fashion. [spoiler]His Shadow's Arcana, for those who missed it, is actually the Moon. It represents staring into the abyss of yourself, as well as facing darkness, danger, and in a negative aspect, a person's nihilism.
Deep down as a Shadow, Teddie's instinct is to kill humans, or at least it was. This is why his Shadow was so much more dangerous to everyone, as opposed to most other Shadows, which were only a danger to their hosts until the team attacked. It directly addressed and threatened the entire team, though that may have been in part down to Izanami's intervention with Teddie's shadow in particular, which was stated multiple times to feel different to other Shadow selves.
However, Teddie's own Arcana is the Star, which represents self discovery following one's darkest overcomings, as well as a thirst for knowledge and/or power. Mostly the latter in Teddie's case.
It's actually possible Teddie's Arcana was the Moon before his Shadow came along. The nihilism, destruction, depressions, and Shadow instinct largely vanishes after Teddie acquires his Persona. He becomes more socially open, and not just in the perverted way he was before (which again falls under base instinct.
END PERSONA 4 SPOILERS
As such, it's possible, and in fact likely that an Arcana can change and be different between Shadows, people, and personal journeys.
Well, I can't blame you for not knowing, since I role-play as a P4 character. But I seriously never got around to beating P4. I put it on a long hiatus during Naoto's dungeon, due to my hatred of non-handhelds. I recently started playing again though, and I beat Shadow Naoto less than a week ago.