Aka Williams (아카 윌리암스, Aka Williamseu) is the leader of a group of Regulars who are getting on the Hell Express. His subordinates call him "Sir Aka" most likely out of respect and/or fear of the man. He was previously on board the train with his allies and participated in the Dallar Show as part of Jyu Viole Grace's team. However his main focus was stopping Hoaqin.