User blog comment:Bo-Katan/Thawne and Time Remnants/@comment-1854917-20171203141113

How Eobard survived and appeared on Earth-X remains to be seen. My theory is that it was done by  Mallus, main antagonist from this season of Legends, who is resurrecting villains through some sort of magic. It might as well be because one of time remnants was able to breach to Earth-X and was therefore unaffected by timelines changes, but this theory has a lot of plot holes.