I've edited the _DS_MENU.DAT into displaying my Wii Clouds skin, I've changed a few things about it, and quite a few aspects of the buttons etc, so this _DS_MENU.DAT works best with no external skins added
I don't have a wii u anymore to test it myself, but if homebrews are not visible on the wii u menu I think you can press L + R + minus to open the plugin menu, there should be an option called "homebrews on wii u menu" or something similar
Or when your player dies, you can say in code, if enemy exists, do nothing, but if enemy does not exist, then create enemy at certain spot. (This would be a pain tho for lots of emeies)