I ran duocolor for several chapters and would run out of the right color at least once every few battles. Even with a perfectly even deck unless you only use a color you have 3+ cards in right now, you have more of to start every chain you're going to run out sometime. And even then there's going to be situations where those 3 cards are like, 3 healers when you need to put down 2 melees and 1 healer.
And once you have a good selection of monsters, the increase in variety isn't particularly notable. There's maybe two or three really good monsters I wish I could put in my monocolor decks but it's really not a big deal or remotely worth losing a turn or mana bonus here or there.
I read my situation and i play a card, for example if i have only two yellow cards i play blue cards, but usually even if play a yellow card a third yellow card appears in the meantime, and i don't have a perfectly even deck.
The type of monsters doesn't really matter in the end, obviously melee monsters are better than others to fight, but any monster with monster fusion and power ups from the 3 cards stuff becomes good enough, in the end it's not important how much damage a card can do in a single turn, but how much damage it can suffer without dying, because the more it lasts the more it heals and becomes powerful, that's why a healer behind is more important than a powerful monster ahead.
. The visuals just pop off the Vita's screen, the combat system is quite creative, the cast is very lively and the references to gaming are just a joy to see. Great purchase from the Vita Birthday sale and once more Gaf sells me on another JP gaming series 
