How about the best performance of the month (considering if its an important fight or not) get a special card?
for example, 16th September we have Golovkin vs Canelo, their division is in the game and lets imagine Golovkin wins. Golovkin would get a special card, higher rated than the normal Golovkin card and with another color, maybe orange, i dont know
October we have Joshua vs Pulev, I think its the biggest fight we have that month. The winner gets the special card, and so on