Arche-Penthesilea (アルゲー・ポリデュークス, Arugē-Poridyūkusu)? is the second boss of Persona 3 Em and the Arche form of Akihiko Sanada's initial Persona Polydeuces. It is encountered on the 40th floor of Oneiros.
- Persona 3 Em: Boss
The Arche persona symbolizes a part of a person that they do not fully understand and that is difficult for them to accept, similar to the function of shadows in Persona 4. What that entails for Akihiko is unknown, however the pre-battle dialogue options are "I don’t know what to say" and "You are enough".
The stats of Arche-Polydeuces mirror those of Polydeuces, which also symbolizes its shadowy, opposite nature.