Sickeningly

Sickeningly is an adjective which means causing or capable of causing sickness, especially nausea disgust or loathing.

Some of the definitions written for Urban Dictionary by teenage spite monkeys are sickeningly repulsive and graphically demonstrates their childish, self-aggrandising stupidity.

sickeningly beautiful

A tragically beautiful person. Someone who remains beautiful (not necessarily in a skin-deep sense) through treachery and hardship.

For example, it's the end of the world, or in some dystopia after a large battle or some kind of tragedy.

"God, even in the ashes, covered in blood, dirt and other grime, they're sickeningly beautiful"

or

Possibly at a funeral, or maybe in the ER.

"Even after everything that's happened, they remain sickeningly beautiful, even in their grief"