I don't listen to your genre but I get what you mean. I love songs that can be both pretty and also intense.
You probably don't like this kind of stuff because it's older but here's a few examples of the kind of songs i'm talking about when I say they start pretty but end intense.
Fleetwood Mac - Silver Springs: https://www.youtube.com/watch?v=iVsy717Ej7U
(Starts out as a beautiful sad song about her ex, and like 4 minutes in it becomes more of a desperate, angry, angsty, intense yelling as she sings "I'll follow you down til the sound of my voice will haunt you! You'll never get away from the sound of the woman that loves you!")
Fleetwood Mac - Rhiannon: https://www.youtube.com/watch?v=MtPyk8_onO8
(Stevie Nicks, the female singer who writes & sings both of these songs does this alot. She starts out singing sweetly and very pretty and builds the emotion until the end and then it becomes a really intense, crazy song. In the live versions of this song Rhiannon, she sings the song and then like 4 minutes in she sings a verse slowly and quietly a couple times and then she loses her sh*t in the end and it's like an exorcism. She's a pretty rad chick.)
Hole - Violet: https://www.youtube.com/watch?v=cH_rfGBwamc
(Another female singer/songwriter who is really intense. Courtney Love starts this song off pretty and really quickly it becomes screaming.)