hate
婞 centers on intense negative feeling: hatred or resentment. The meaning is narrow and strongly emotional.
婞 combines 女 (woman) with 幸, but the historical role of 幸 here is uncertain. It may have been a phonetic component, but the exact origin is unclear.
A woman 女 beside 幸, but here the feeling is twisted: imagine a woman whose good fortune has turned to bitter hatred.
For ケイ, picture a hateful person throwing a cake at someone: cake -> ケイ, and the spiteful act matches the meaning of hate.