Proliferate allows you to choose any number of permanents and/or players and add another counter of any counter they already have
All the legends in these decks have a unified goal of working together within their decks theme and its fun building cards like this to have that creative team synergy, whether thats sayinteracting with counters in Final Fantasy X or playing with the graveyard in Final Fantasy VI
Kuja, Genome Sorcerer / Trance Kuja, Fate Defied Strangely enough, I rather think Kuja, Genome Sorcerer is the better half of this double-faced card
Give it double strike to get both of the hideaway cards when you first connect with an opponent, and then blink it with something like Conjurers Closet to get the hideaway triggers again
There will be some consideration given to the mono-color, two-color, and three-color categories
This slate is broken with burn since you are already aiming at people's face with stuff and now more