Here's a tool that will let you simplify illustrations and animations.
Have a look at project Anime2Sketch, a sketch extractor that helps turn illustration, anime art, manga, and all kinds of animations into sketches. The app is based on the paper "Adversarial Open Domain Adaption for Sketch-to-Photo Synthesis".
The project page notes that the app works best illustrations and lets users turn hand-drawn photos into clean lineart. You can also simplify freehand sketches and even turn animations into sketched sequences.