Actually rather worried for Emerald's future in the series. We saw what Salem does to people that fail her, and for Emerald, Mercury and Hazel to return to Salem without the Relic, lost the Fall Maiden, lost the cooperation with the White Fang, and let the Spring Maiden slip from their fingers, I can foresee it being a meeting not ending well…

I doubt she'll wind up dead though. She's a good fighter with a powerful semblance. The only reason she killed Leo is probably because his usefulness was entirely connected to his position of power, which he would have has no way of maintaining after this.