CAST AND PIERCE, UNTIL IT IS DONE
Although I wonder how he actually managed to not die after encountering her if he was much weaker and low level at that point. Maybe his particular specialization (some sort of blood/flesh manipulation apparently) allows him to regenerate from a far wider range of damage and she assumed he was dead (and/or got immediately distracted by something stronger).
Also cool to see Fern's extreme stealth skill that came up all the way back at the very beginning of the series is still playing a serious role, allowing her to avoid magic detection even by fairly skilled counter mages.