Quote from Yandere Sliver »
There are 46 themes.
A theme can have one of three rarities: common, rare, mythic.
A common theme has 4 variations, a rare theme has 2 variations, and a mythic theme only has 1 variation.
Dog is a rare theme so there are 2 Dog decks. 2 variations of the same theme.
Overall there are 121 variations, so when you open a Jumpstart booster you open one of these 121 half decks.
Quote from Hunter »It has been confirmed that there are 46 themes.