Favorite Fantasy Moments - Violent Magic

Geeking out over epic spells and multi-faceted witch characters is so much fun! So it hurts when something too violent to believe happens in a story and you're left thinking, "What just happened? No way that could actually go down."

What is your position on violent magic in fantasy? Do you see it as just for fun, or serious? What are some of your favorite--or least favorite--moments involving violent magic?