Disney Lorcana cards each have types based on the origin of the character pictured, and their role in the story - these are varied but include descriptors such as Storyborn, Princess, Ally, and so on
Nyxthos, Shrine to Nyx is the extremely powerful mana engine of the first "best deck" in Pioneer
This is already how it works for double-faced cards, so it makes sense for the same rules to apply here
Toss in additional mana discounts like Cloud Key and Ugin, the Ineffable, and a lot of the cheaper colorless creatures are going to be free to cast
Thus we have an exciting time for Explorer
For just four mana, all of your creatures can take someone, if not everyone out of the game so long as they take just a total of ten damage