halberd
戛 centers on a halberd, a type of pole weapon with a blade. The meaning is specific to this weapon and does not extend to broader abstract ideas.
戛 combines 戈 (halberd) with a top element that may have originally depicted a head or face, but the exact historical development is uncertain.
The bottom component 戈 is a halberd, and the top part looks like a head with a crest. Picture a warrior holding a halberd with a distinctive headpiece: 戛 is that halberd.
For カツ, imagine a warrior cutting with a halberd: the sharp cut sound cues カツ.