menacing, dignity, majesty, threaten
嚇 centers on projecting an imposing presence to intimidate or command respect: menacing, threatening, or displaying a dignified, majestic authority that deters others.
嚇 combines 口 (mouth) with 赫, which likely contributes both sound and the idea of blazing red or intimidating brightness, suggesting a threatening or commanding voice.
A mouth 口 beside a blazing, intimidating red 赫: imagine a fierce shout that makes others feel threatened and see you as majestic.
For カク, picture a menacing figure giving a sharp 'cack' sound: cack -> カク, and the threatening shout echoes from the mouth.