Out of the mist they stepped-into the mist what does it mean?

When referring to a bombing victim, it is when a person's body is blown up by a bomb and nothing remains except the tissue fluid. This fluid that sprays through the air is pink mist. When referring...

It means manure. It is a mild way of saying manure as an interjection as well--though it is not nearly as offensive as it is in English. Its nuance is closer to "darn it" or "shoot," etc.

the mist is about clouds of mist trapping people inside a store because the mist had flesh eating monsters.

The term Mistgöre is an extremely impolite term for a child. It doesn't really have an English equivalent but Göre translates as brat.