happiness, luck
倖 centers on good fortune that comes unexpectedly: happiness or luck that arrives without effort.
倖 combines 亻 (person) with 幸 (happiness, luck), suggesting a person who encounters good fortune. The exact historical development is uncertain, but the component relationship is clear.
A person 亻 standing beside 幸 (happiness) represents someone who has stumbled into luck: 倖 is unexpected happiness.
For コウ, imagine a person who finds a lucky coin: coin sounds like コウ, and the coin brings unexpected happiness.