Crimson Burn

(Art is not mine, credit goes to artist)

Hanahaki Disease-
When a person coughs up flower petals and grows them in their lungs from an unrequited love.
Can be cured if the person reciprocates their love
Or can be removed with surgery, but the persons romantic feelings will vanish permanently
Can cause death if feelings remain unrequited, they refuse the surgery, or the flowers have completely overtaken the lungs and causes the person to stop breathing

A petal falls from the young hero's lips as he flies through the night sky after a long day of work.

A villain burns with envy and pride as he continues his reign of terror on the city he hates.

What happens when these two keep running into each other?
What happens when they're involvement with each other becomes to much for them?
And what happens when another petal falls from the heroes lips?

(Told from the perspective of mostly hawks but will also have Dabi POV as well.)

CONTAINS MAJOR MANGA SPOILERS
(Also, I am gonna make up a timeline that is as close to canon as I can get because it's relevant to the story)