Can you "reset" amiibo level data?
Yes, as of Wii U software update 5.3.0, the System Settings app has an Amiibo section, including two ways to remove data stored on the figure's chip:
- Erase Game Data - Removes the game-specific data from the figure.
- Reset Amiibo - Removes all data: the game-specific data, and the figure's nickname and owner.
Sounds like you're looking for the first one.