Quote Originally Posted by WellGramarye View Post
Graha's time travel IS normal time travel, as Elidibus ghost warns us, if we go back in time and change anything, then the present we come back to will not be the same one we left from, and that we should be careful about that. He thinks this won't be a problem because we will be so Aetherically thin that we won't be able to have an affect on the past, but once we are there Emet-Selch and Hythlodeus change us into a form that CAN have an affect on the past, thus now causing a paradox.
Incorrect, Elidibus's exact words are:
"Yet even should you be able to interact with others, you will be unable to effect meaningful change. For the reality you wish to save--the reality to which you must return--exists as a result of the Final Days. You cannot reshape the past to undo the tragedies of the present. Cannot unmake the sorrow and suffering fated to come."
Meaning it was written in stone, there was nothing we could do to change what was going to happen. Any interactions we were going to have were supposed to happen.

Quote Originally Posted by WellGramarye View Post
Graha only ended up on the First because at the time of his jump into the past, the First and the Source had already been merged together due to the U8C. Graha's jump to the past is 300 years into the future after Stormblood. When he went back in time, he went to a pre-merged world and it landed him 100 years in the past (from Stormblood) on the First.
The problem is the world he was going onto was at time/space coordinates different from the Source. The Source itself is mentioned as being the original, meaning the equivalent of (0,0) on an X/Y grid. All the shards are shifted to different locations around the Source, making their coordinates on that X/Y grid different from the coordinates of the Source. Jumping to any of them requires jumping on that grid, and completely altering your location. Considering that the Crystal Tower also does not exist on the place it's going to originally, Crystal Tower and the Exarch are unnatural additions to the First's timeline, which required shifting the location through both space and time.