carve
剞 centers on cutting into a surface to shape or decorate it: carving, engraving, or incising.
剞 combines 奇 (unusual, strange) with 刂 (knife). The knife radical suggests cutting or carving, while 奇 likely contributes a phonetic element. The exact historical development is uncertain.
A strange (奇) knife (刂) is used for carving intricate designs. Imagine an oddly shaped blade that makes unusual cuts.
For キ, picture a key (キー) being carved from wood with a strange knife: key -> キ, and the knife shapes the key.