Board Thread:Questions and Answers/@comment-28265951-20160421125919/@comment-27934866-20160915033249

Eobard Thawne:

Eddie Thawne's death has erased his family generation out of existence in the current timeline, but due to Eobard's time travel abilities and his connection to the Speed Force the Time Remnants appear from an erased Timeline in order to keep his personal Timeline as well as the new Timeline intact and prevent further Time Paradoxes. Eobard's younger self appearing in 2016 ensured he knew what time period Barry was from, and kept his future Time Rupture as Harrison Wells intact by meeting Harrison Wells of Earth-2.

Basically whenever Barry meets Eobard over the next 8 years it will be a Time Remnant, and he won't be able to kill or imprison him because it will cause a Time Paradox, until time catches up with him in 2015 when he's erased from existence. Which is why killing his younger self won't save Nora Allen because she's already been killed by his future self making it a fixed point in the Timeline i.e. It has to happen in order to preserve the Timeline.

If the situation is a person comes to this this time period for the first time, but their future self has already done something in the past to change the Timeline it's a Predestination Loop i.e. Fate cannot be changed/Fixed Point, but if it's a case of going back to change something you, or someone else has done but the Timeline is preserved it's a Time Rupture i.e. Fate can be changed/Flux Point. However as we all know if something is done in the past that completely alters the Timeline it's a Time Paradox.

Hunter Zolomon:

His Time Remnants are created by running fast enough to travel a few moments into the past, so the version of himself from a few moments ago becomes the remnant of a time that no longer exists because he doesn’t need to travel back. The thing that confused me the most is despite the effects of Velocity Drugs being temporary, I was unaware it made his natural Speed Force undetectable, and that until absorbing Barry's speed he was reliant on the Drug. It made me think that when Zolomon first came on screen he was a Time Remnant (due to the fact the Speed Force wasn't detected in his system, and when he used the Velocity Drugs his lighting never turned blue). However we know the Time Remnant was created after Barry, Cisco, and Harry went to Earth-2.