Complex sentence: The evil Diabolyn was a stepsister to the late Queen Sarana (voiced by Amanda McBroom), whom she always considered weak and unfit to rule, and in order to gain her "rightful" throne she allied herself with demonic Spectres.
Split into simpler sentences: The evil Diabolyn was a stepsister to the late Queen Sarana (voiced by Amanda McBroom), whom she always considered weak and unfit to rule. In order to gain her "rightful" throne, she allied herself with the demonic Spectres.