[Ducky]

and as I think it's the previous block and the current block that you will find in shops. So a total of 6 different sets available through regular stores. The other block we can get right now is the Mirridon block, in which infect was introduced, i think.

so, technically, if you want to improve your infect deck you're better of getting the mirridon boosters. They'll have a lot of infect creatures in them.