The Cross Marks are abandoned "bar codes" of Eden. Eden believed them to be valueless, as they did not have powers that were very strong. These people are marked by a dark X on them.
In chapter 158, when going through the secret entrance to Eden, Ogami and his companions meet a bunch of them, who try to kill them even by sacrificing their lives to prove their worth to Eden. Yuuki explains that they are like him and shigure, so called bar codes genetically engineered humans for the purpose of creating strong power users. He too reveals that the crossmarks are bar codes, who are regarded as weak and that being a Cross Mark is a fate worse than death for a barcode. Most of them are later killed by Utah of the Mirror.
He explains that bar codes are meant to be the elites and have a purpose, unlike the crossmarks. He then attempted to kill them all, until Yuuki intervened. With their last bit of power, the Cross Marks gave their powers to Yuuki, restoring those he lost in his fight against Ogami, unlocking Yuuki's Voice of Life and status as the "Apple" of Eden.
Yuuki blames himself for his inability to save the Cross Marks, while the others remarked that Eden was much more sinister than they had appeared.
Powers and Abilities
The Cross Marks behind the door showed the ability to absorb powers. Another group of them showed the ability to fire out 'waves' of energy from their mouths.
Known Cross Marks
- The Cross Marks are likely a reference to the experiments of the Mibu Clan in Akimine Kamijyo's ealier work, Samurai Deeper Kyo.