What's the plural form of unvirtue? Here's the word you're looking for.
Answer
The noun unvirtue can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be unvirtue.
However, in more specific contexts, the plural form can also be unvirtues e.g. in reference to various types of unvirtues
or a collection of unvirtues.