This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
怇 combines 忄 (heart/feelings) with 巨, but the exact historical development and original meaning are uncertain.
The heart radical 忄 beside 巨 suggests a large or exaggerated feeling, but the exact meaning is unclear.
For キョ, imagine a giant (巨) heart (忄) feeling exaggerated emotions, and the sound 'kyo' echoes the surprise: キョ.