In the comics, Killer Frost's death varies depending on the specific storyline. Sometimes it's due to a powerful enemy or a self-sacrifice to save others.
Killer Frost gained her powers through a scientific accident involving cryogenic experiments. This exposure transformed her and gave her the ability to control ice and cold.
It depends on your preferences. Some people think it's great for its intense storylines and well-developed characters. Others might not be as impressed.