Question What do I need to do this?

[Onerabidmonk]

I hate streaming mkv because pausing/ff/rw always messes everything up.

I'd like to be able to use my phone as an interface to download mkv to storage attached to hardware that can play 4k mkv to my TV.

Any ideas?

 

[hang-the-9]

I can't really sort out what you are trying to do here, are you saying you want to play the files off your phone from your network storage? VLC media player should be able to do that and you would need an MHL cable for your phone to connect it to the TV for playback.