[quote=thewizardguy]
Okay. I was just wondering if this thing could be used to just go back in time, because that would be a pain.
[/quote]

Conceptual weapons like Fragarch and Gae Bolg are soul crushing weapons, but they only do what they're designed to do, so they have limitations and counters. For example, after this point you should know not to use a trump card against Gilgamesh, thus Fragarch will no longer be a problem.

For example, using Fragarch on Gae Bolg would result in a double KO.