How to "reopen" an Epic/Initiative when new feature coming

[George]

Hello

In my compnay we are starting a new initiative, however i guess we will have in near future several initiatives merging all into same product we want to build, so far not the case and not really full visibility on needs/use cases for them.

So we are starting with this new one and try to make it as generic as possible until we have more details but i was wondering how to solve a doubt that i have in my jira project.

Should i create a Epic for a use case, which at the end is the one bringing a functionality to a customer (even if maybe this epic will be an mvp) or should i create different epics for the full use case as at the end many of those bricks used in this case may be used in other initiatives.

Once solved that, how should i create the initiative or epic(s)?, meaning, i may create an epic for the full use case of for a brick of this use case releasing an mvp but x time later i may want to add a new feature to a brick or use case which but since i have releases this mvp, epic is close. 

Should i handle this through Epic names such as phase 1, phase 2.... or keep always open the epic(s) and handle this through releases?

I know it may not be an easy question but really wont like to finish as a messy jira project since im not really in favor to keep open Epics as they should have a start/end but this epic will never be closed in my closed as new featuers will come always.

Thx for your support

Jorge