User blog comment:B214/Volume 21 info & spoilers/@comment-222.124.122.111-20160626015201/@comment-1359322-20160626040728

""The evil god Loki from thirty years from now, during the war, broke out of jail through a gap that he had discovered. Thus, he ended up joining the war on the side of our opponents. Using a technique from the parallel dimension, he was able to cross over space-time, finally arriving in this time period.""

- EX Chapter 1