brand
剠 centers on marking with a hot iron: branding, as in permanently marking skin or property. The given meaning 'brand' is the sole core idea.
剠 combines 京 (likely a phonetic component) with 刂 (knife), suggesting an action involving cutting or marking. The exact historical development is uncertain, but it likely relates to branding as a form of permanent marking.
The left side 京 looks like a tall structure, and the right side 刂 is a knife. Imagine a hot knife pressing a brand onto a tall wooden pillar, leaving a permanent mark.
For ケイ, picture a branding iron shaped like the letter K: K -> ケイ, and the hot K-shaped iron brands the surface.