Is he really changed, or is Thawne the same?
Okay, we all know the answer to this in some way. Eobard Thawne? Come on, guys, he killed Barry's mom and a dozen other people, created Grodd, and created the evil metas!
But the important thing to note is that there are Two Eobards right now.
Here's what happens.
Sometime between here and 2024, Barry meets Eobard Thawne for the first time. Thawne learns he id destined to become his hero's archenemy. Time is a fickle thing, and Thawne replaced Cisco as Fate's Fool, forcing himself to hate Barry. Then, in Season Two, he finds Barry's real name, but before he goes to kill Barry in the past, he wants one last chamce to gloat, running to the future and battling Barry in the Crisis of 2024 (or 2019, if Nora continues her games). After going back in time with Barry, the two battle again, and Barry saves Young Barry, while stopping Other Young Barry from creating Flashpoint. Older Barry, along with Thawne, loses his power to time travel because if Barry never became the Flash, Thawne never learned about him, and never became Reverse Flash. It's a Paradox, meaning that somewhere in the timeline, there's a Barry that couldn't Run Home to You because he didn't regain his ability to time travel for 15 years. By this time, Iris had began to hate The Flash as well because Barry's alter-ego had forced her to live a life without her husband, raising her child alone.
Anyway, Thawne kills Harrison Wells, becomes Harry, and creates the Particle Accelerator. He gets erased from existence, recreated by Flashpoint, and killed by Zoom, but maybe Time Remnanted himself in order to survive the death Barry told him (Season Two) was coming. Thawne went to Earth 53 to work for Evil Oliver and then later returned and was held in Iron Heights Prison, wherein he begins working with Nora.
My favorite Barry Allen moment is when he turns to Nora and says that no matter who it is, anyone, even Eobard, can change. Not only does it reference Barry's secret superpower of Hope, it also gives a valuable life lesson that we've seen before, with Magneto, Killer Frost, Doc Ock, and even everyone's favorite Sith Lords Maul and Vader!
I hope Eo turns out good. I'm saying right now that i think he may be.