I got the inspiration when thinking about gambling and the idea of when playing card games the cards are sometimes "hot" and sometimes "cold" - which connected with our Fire and Ice theme. I then thought of the face cards and how that pulled in concepts of royalty and lots of gold, which would allow me to bring in the whole Steel typing thing. Also, I immediately thought of having the forme change be King and Queen formes, with the KIng being big and defense-oriented, and the Queen being more lithe and offense-oriented. I chose the Diamonds suit for a couple of reasons. Since it is a red suit, it allows coloring that works well with Fire typing, and red gemstones like rubies have long been associated with the sun and fire in many different cultures. Also, diamonds allow me to put some crystalline elements in the Queen forme, to support more of the Ice typing.
In general though, I really don't want to just slap any direct typing indications on these designs just... because. Like, I'm not gonna put flames on these just to scream to everyone "Hey look, these are Fire types!" I'm not saying there is anything wrong with doing that, and I certainly do that on most of my CAP designs. But this time, I want to let coloring and the general design theme hints carry the burden of supporting our chosen typing.