This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
魕 combines 鬼 (demon, spirit) with 幾, which likely contributes a phonetic element. The exact historical development is uncertain.
A demon (鬼) with a complicated inner shape (幾) suggests something mysterious and hard to pin down, fitting its unclear meaning.
For キ, imagine a key (キー) unlocking the secret of this mysterious demon: key -> キ, and the demon's meaning remains locked away.