AAU allows cards to have mods (hair, clothes) embedded directly into the card file. These are auto-extracted when the card is loaded, preventing "missing texture" errors.
You can download pre-made characters from various community sharing sites or "card boorus". artificial academy 2 how to install cards
If you use the AA2Unlimited (AAU) modding framework, the process is even easier: AAU allows cards to have mods (hair, clothes)