Jamon:
Orfen was the most ambitious one of the three sisters. She felt that she should been the leader of the Aracna, not Nerupa. While her sister Lithra disappeared without a trace, Orfen declared she would create her own powerful forces and left the Aracna to settle in the Sea of Spores.
Now Orfen is using the Energy of the Sea of Spores to make herself stronger. Orfen's Handmaidens Arima and Arimus are collecting the energy at the Sea of Spores.
Orfen's Handmaidens have covered themselves with a barrier of the Sea of Spores to protect themselves and they're sending the Energy of the Sea of Spores to Orfen. If you want to defeat Orfen, you'll need to destroy barrier of the Sea of Spores worn by Orfen's Handmaidens, defeat the handmaidens and stop them from sending the energy to Orfen.