Billy Batson,

If Billy and Angel are adults, here's another different idea, without villains as the focus and with more development.
"Between lights and secrets"
Fawcett City changed completely when night fell.
The offices were closing, the streets were filling with neon lights, and a few blocks from downtown, Club Euphoria was opening its doors. It was a place known for its dance shows and live music. Angel Mackenzie worked there, a dancer who had spent years perfecting each choreography.
It wasn't a temporary job.
It was the place where he wanted to prove that he could make a living doing what he loved.
Billy Batson knew her before she got that job.
Theirs was one of those friendships that seemed impossible to break. They wrote to each other every day, argued over silly things, and ended up laughing five minutes later.
However, since Angel started working at the club, they hardly ever crossed paths.
She worked at night.
Billy... disappeared every time the city needed Shazam.
One early morning, Angel finished his presentation and went out to the back alley to get some air.
He found Billy sitting on the hood of his old pickup truck, with a bag of fast food in his hands.
"You're late," she said.
—And you go out late?
-Draw.
Billy picked up the bag.
—I brought you potatoes.
She smiled.
—I forgive you.
From that night on they began a routine.
After each show, Billy would wait for her outside. Sometimes they would talk for ten minutes. Other times they would drive to a lookout point overlooking the entire city, which was illuminated all over.
It was the only time of day when they could both forget about everything.
Until one night Billy didn't show up.
Angel waited ten minutes.
Then twenty.
After an hour, she left on her own.
The next day he received a message.
Sorry. I had an emergency.
She did not answer.
I wasn't angry...
I was tired of there always being an "emergency".
When they met again days later, Billy noticed that something had changed.
-All good?