Euphemism vs Dysphemism

What is the difference, when does each apply, and can both be at work at once.

Language

Euphemism

Replacing a blunt or unpleasant word with a mild or technical one, so that the audience is spared the reaction the plain word would produce.

Language

Dysphemism

Replacing a neutral word with a harsh or contemptuous one, so that the audience's distaste for the word attaches to the thing it names.

The differences

EuphemismDysphemism
DirectionSoftens. A mild or vague word for something harsh.Hardens. A harsh or loaded word for something ordinary or neutral.
PurposeTo make the audience accept or overlook something it would resist if plainly named.To make the audience reject or fear something it might accept if plainly named.
Classic examples"Collateral damage", "enhanced interrogation", "downsizing", "passed away"."Death tax", "regime", "scheme", "swarm" for a group of people.
Who uses itThe side that did the thing, or wants it done.The side that opposes the thing, or the people.
The counter-moveTranslate into plain words and see whether you still agree.Translate into plain words and see whether you are still afraid.
The tellThe word is vaguer than the thing.The word is nastier than the thing.
An example of euphemism

A ministry announces that a hospital will be "right-sized" and services "consolidated". The hospital is closing.

An example of dysphemism

A tax on inherited estates above a high threshold, paid by a small fraction of households, is called the "death tax" in every statement by its opponents.

Can both apply?

Not to the same word, but constantly to the same subject: the two sides of any dispute will euphemise their own position and dysphemise the other's, so that the same act is "enhanced interrogation" to one speaker and "torture" to another. The reader's task is the same either way: find the plain word, which is usually the one neither side is using, and judge the thing by that.