Combo decks that are soft to discard spells can gain a lot of redundancy by slotting in a few copies of Wish, and having a copy of their relevant pieces in the sideboard
That being said, there is a place for coloured-back sleeves, for example with Marvel Champions, we have our individual decks with coloured sleeves to tell our decks apart, as were both using similar player cards that can be played under each others control, and it can be easy to get cards from each others decks mixed up in certain situations
You can play with regular old uncommons as your leader
This is still quite powerful, as goading not only leads to another one of your opponents taking damage, but it also prevents you from being attacked by the creature at hand
These are Japanese-exclusive promotional cards, historically bundled with CoroCoro Comic magazine subscriptions in Japan