User blog comment:Gourgeist/Shingeki no Kyojin Chapter 64 Review: Welcome Party/@comment-199.79.168.163-20141215164608/@comment-199.79.168.163-20141216021325

Either he is related to Historia and Rod, or Frieda had some other power that isn't the coordinate and that Eren can't use. Though Grisha seemed sure that Eren would be able to use the power so its hard to say.