Today's cards are a vertical cycle. A vertical cycle is a subset of cards that do similar things with bigger or more powerful effects at higher rarites. You can see some examples here. The common and uncommon parts of the cycle may seem familiar to you, as they are similar to Dragon Fodder and Hordeling Outburst. The second set in the Frostmere block is called Hellfire, and devils play a large part in the set, mainly using 1/1 Devil tokens.
The rare part of the cycle gives tokens, but also damages you each turn. This may seem like a drawback, but trust me. In this set, you will wish there were more things that could let you damage yourself.
The Mythic entry to the cycle is a familiar face to some. All of his abilites revolve around Devils. You can pop him right away to get 5 1/1s with no questions asked, or, if you have some other Devils around, wait and see if you can do some other cool things.
I am developing Frostmere and Hellfire together, so they will play nicely with one another while being very separate entities.