Do you know the game Mafia? The idea of this game is the same. The only difference is the story and the roles. The role of this card is the witch. Each night she wakes up. One time in the game she can kill someone (the red potion) and one time she can save someone from the werewolves (the green potion).
To print this, I used the multipass technique described by @makeanything in this video. So first print the color files and then the back file in black.
This is the first card I made. For all of the cards I used OpenSCAD, for this one I used only circles and squares. But for cards I made later, I also used Inkscape and then converted the graphics to OpenSCAD.