Rhode stipulated that he would bring 5000 soldiers to the Winter Castle, but where could he find that many of them?
Not only Marlene, but other members such as Marfa, Joey, Randolf, and Sol also had this doubt as team leaders of this fortress. However, all four of them held vastly different duties. Marfa was responsible for frontal attacks and maintaining order in the fortress. Joey led the Thieves and was mainly in charge of investigation and observation. Randolf's team of Rangers was responsible for scouting and defensive duties outside the fortress. As for Sol, his subordinates of half-demons were mostly in an elite squad who followed Rhode closely and only helped Marfa maintain order in needed times.
