At the basis of any emotional story event is a deep interest in character. It's best if we can relate strongly to the protagonist, or like them as a person. Sometimes we root for a character because of the fantastic enemy, even if you'd punch the character in the liver if you met them in real life. Some writers use kittenish softness to gently lure us to tears; others use chainsaws and pliers to rip open our chest cavities, wrench our hearts out, and chop each blood-filled chamber into poisoned, jaded bits. You know. To get the point across.