when doing that, go to mania mode, get debug mode (note: debug mode will be locked agian when restarting the game)

select a sonic and tails file ofc

only works with that, anways press y button and if u see the the computer ring i think, press A to switch it

and ofc when seeing the last one

press x to place it and get the knuckles face right and boom

KNUCKLES AND TAILS

only works on sonic mania plus

cuz if not, u wont have encore mode and u cant do knuckles and tails ofc

soooooooo good luck

i also did this on the switch so this also works on other consoles but im using the switch ofc

so have fun with it