When Angel tries singing the demon back, Mok is in full Smug Snake mode. When Omar joins her, and the demon reacts, Mok wears a thoroughly perplexed look. When it starts retreating, Mok starts a This Cannot Be! panic before Toad deals with him in revenge for his brother Zip’s Heroic Sacrifice.
Angel deserves an extra mention for her bravery. While she's trying to sing the demon back to its dimension, it begins to envelop her. Despite the danger, she continues singing because she knows more people will die, and only raises her arms to shield herself before Omar joins her. She may have been a Damsel in Distress throughout the film, but Angel was insanely brave when it counted the most.
The Uncle Mikey scene. In addition to being one of the best scenes of the film, it's a straight-up slam of moral relativism.
Angel defying Mok, fearlessly telling him that she's the one with the voice necessary to summon the demon and she's not going to do it. Mok for once completely loses his cool and Angel is still defiant, as Mok storms off. In the original version, Angel then says that if she can sing up the demon, she could sing it back.
Angel: (angrily) If I can sing it up, I can sing it back!
Not to mention she keeps her defiance even as he's strangling her.
Again, gotta give the Devil his due with regards to Mok. In the same scene, Angel tries to flatter his ego by flirting with him and attempting to persuade him to abandon his plan in favour of eloping with her. Mok, having read the Evil Overlord List is not taken in by the heroine and rebuffs her attempt telling her "I've enjoyed your little game, but tonight, the game is mine!"
Omar finally admitting his love for Angel by joining in her song. Their love for one another is so strong that it's able to drive the demon back into Hell.
