I am simple in that. I would just use animated images for most if not all what you describe. For character updates I might take inspiration from those pokemon style evolution or level up pictures.
But from a more pragmatic view, people are not used to click on images to see more information. Not on Itch. They might mistake the layered image for an ingame image.
You might be interested in the spoiler method. https://itch.io/t/2151831/adding-spoiler-text-to-your-game-description You can hide information even without css.