Talk:List of Episodes/@comment-82.156.75.137-20150525121928/@comment-45.50.98.16-20150722215152

im guessing he knew because the moon was never red. as shown in previous clips of the season, the red moon signifies something concerning his mother cordelia. also, shown in the beginning of the season, ayato and his brothers knew about the awakening. thus, when the moon turned red, each and every brother had a reaction they had probably experienced before and flinched knowing something was not right. yui on the other hand, was already undergoing the awakening with the heartbeats each brother knew about, so they would only instinctively relate their rare emotions towards yui.