@digidoggie18 

How is the C7 configured?  The A7 being in AP mode it will need to be phyiscally connected to a device acting as a router.  If you are trying to wirelessly link the two routers together than its not AP mode but WDS you would want to use.  WDS essentially turns the 2nd router into a wireless range extender, and the A7 at that point would use the root or host SSIDs.  If you were hoping for a single SSID that would be the Smart Connect option.  Keep in mind only the C7 V5 and up features Smart Connect.  So if you C7 is a V4 or below you would not be able to use smart connect to create a single SSID.  

@digidoggie18 

For the C5 what i was asking about how its configured is if it was configured as a router or AP.  You clarified that in your response that it was configured as a router.  What you are asking for is possible but only if you use the Archer A7's WDS feature and essentially turn it into a Range Extender.  In AP mode the wireless SSIDs would be separate.  Even if you manually change the SSID names and passwords to be what the C5 is broadcasting, it would still be a separate AP and could cause conflicts in your network for clients that at between the two routers.  There is a solution though.  The Archer A7 has a feature called OneMesh.  With this enabled and using Compatible Range Extenders or Powerline Adapters you can create a Mesh network that all devices in the network will broadcast the same SSID and act as a single network rather than a network with 2 APs in it.  

If you need Ethernet from the remote nodes (RE or PLC) I would recommend the RE550 or RE315.  a full list of compatible RE and PLC can be found here