JKSManga
It could be Cindy becaise she cried when hearing Rowa’s death; It CANNOT be Bryce because during the time when the King use his blood control ability to defeat Rowa, Bryce said he would not be using such an ultimate move to a weakling, while at the same time another leader was screaming and questioning why Rowa decided and revealed himself to attack the 10th. It could also be Jill, but there is no connection so far besides wanting revenge during Fex’s execution. Then it can also be the leader with club, again there is not enough information to connect him too it! Those to me are likely the candidates for the being Bloodsuckers, but again it could also mean the others such as the 3, 7, 11 & 12 since they have been a mystery!