Couple of custom super buttons with Deadpool and Wolverine on them, will print even better with a smooth texture build plate if you have one.

Installation note: The grip the MX stem has on the key switch itself is stronger than the hot-swappable mechanism that 8BitDo uses to keep it attached to the board.  It's likely that the stock keycap and these ones will pull out the switch, all you have to do it pull the switch out of the cap and reinsert.