Custom Animated Cards - Monster-Train-2-Modding-Group/Trainworks-Reloaded GitHub Wiki
This page is not done yet, but I will add a blurb.
If you hadn't noticed yes the cards are animated. The animations are controlled via a shader and card animation is specified via a set of layered images along with effects to apply per layer. I have not fully reverse engineered the system enough to make a nice user friendly tutorial out of it yet.
But I have at least dumped the data specifying how each card in the game is animated. View that in my Monster Train 2 Game Data repo.