When you remix, have who you want to fight circled on the difficulty meter, select the stage (in backdrop) Rework the code so it doesn't spring back to the select after clicking the flag, and add in your characters. Keep the difficulty meter shown, but hide the character selection. You'll be good to go after! You have to kill the 5 most difficult characters to unlock OP Cyan Square, press space to find him!
c2a Have fun!
