negation, wicked person
匪 centers on the idea of something being wrong or not right: a wicked person, or the act of negating or denying what is proper.
匪 combines 匚 (box/enclosure) with 非 (wrong/not), suggesting something enclosed that is not right. The exact historical development is uncertain, but the component relationship is clear.
Inside the enclosure 匚 is 非 (wrong). Picture a box containing wickedness or negation: 匪 is a wicked person or the act of negating.
For ヒ, imagine a wicked person hissing 'heee' as they deny the truth: he -> ヒ, and the hiss echoes the negation inside the box.