Despite a tough exterior, Ermes is proud, loyal, and headstrong.

She does not shy away from a fight and is willing to do just about anything to put herself in a better situation whether it is taking a bet that could risk her organs to even splitting her own body parts with her Stand ability despite knowing that they eventually have to be fused back, wounding her severely.

Knowing the ins and outs of prison life, Ermes is preoccupied with acquiring and amassing money to acquire goods and bribe guards.

Ermes shows a severe sense of resilience, as she was still on her feet and moving around even after Marilyn Manson took her liver and survived the shared experiences of suicide attempts from Thunder McQueen. She has a good sense of justice but violently punishes anybody who crosses her way.