fear
恟 centers on a state of fear or dread, often an inner emotional agitation.
恟 combines the heart radical 忄 (emotion) with 匈, which likely contributes the sound and may suggest a turbulent or agitated quality. The exact historical development is uncertain.
The heart radical 忄 beside 匈 suggests a heart in turmoil. Picture your heart pounding with fear when facing something menacing.
For キョウ, imagine a fearful person shouting 'KYOU!' (like 'kyoh!') when startled. The sharp sound キョウ matches the sudden fear.