Jack

X5-417, or "DYLAN", was a member of Max's unit until he died from a seizure. His death came before the escape from Manticore. His death was taken particularly hard by Ben, who had led the others in praying to the "Blue Lady" (a figure based on the Virgin Mary) for Jack's recovery.

He was a very good boy.

Biography
Jack was a member of the X5 unit.