sword
劒 centers on a sword as a weapon. It is a variant form of the more common 剣, carrying the same core meaning of a double-edged blade.
劒 is a variant form of 劍, combining 僉 (a phonetic component) with 刃 (blade) to denote a sword. The exact historical development of this particular variant is uncertain, but it follows the common pattern of phono-semantic composition for weapon characters.
The left side 僉 looks like a gathering of people, and the right side 刃 is a blade. Imagine a crowd gathered around a single sharp sword, the center of attention.
For ケン, picture a famous swordsman named Ken holding this very blade: Ken -> ケン, and his sword is always at his side.