Since I have a friend who currently has no internet, I wanted to know how I would be able to bring him an application on a flash drive.
So running a hypothetical scenario, if I wanted to bring him application X.rpm, which has dependencies y and z, would I need to grab the RPM’s of those as well, or does the RPM of application X already include those?
or is there an easier method of doing this?
You would have to bring all the RPMs. This is called offline dependency hell. 
If your machine and his are identical, you could take along all the RPMs added to your system since the last time you saw him. There’s an option to preserve downloaded RPMs.
You need all packages that are dependencies of X that he does not have allready.
Thank you.
I figured as much, but it never hurts to double check.