far
倞 centers on the idea of distance or remoteness: something far away. Its other recorded senses (strong, clear, seek, compete) are disparate and do not form a single clear conceptual center.
The exact historical development of 倞 is uncertain. It combines 亻 (person) with 京, but the original semantic and phonetic roles are unclear.
A person 亻 standing in the capital 京, looking far into the distance. The capital is a place from which one can see far.
For ケイ, imagine a person in the capital gazing far away, thinking of a distant kay (ケイ) they once knew.