Update on the 3ds situation, and it's not a good one. I got a replacement SD card slot, but while trying to dissemble my 3ds, the right middle screw stripped, and is not not coming out.
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)