anger
怫 centers on the emotion of anger, specifically a kind of resentful or indignant anger that wells up inside.
怫 combines the heart radical 忄 with 弗, which likely contributes a phonetic element. The exact historical development is uncertain, but the heart radical suggests an emotion, consistent with the meaning of anger.
The heart radical 忄 beside 弗: imagine a heart that is not (弗 can suggest negation) at peace, so it burns with anger.
For フツ, picture a heart so angry it's about to erupt like a volcano: the sound 'futs' mimics a sudden burst of fury, like 'futs!' as the anger explodes.
—
indignant; wrathful