Aurelion Sol is "Playing with starfire"

The animated one but starfire didn't look like that. The one where raven was very gloomy agh don't really remember. Starfire looked more teenagerish and more old animeish.

Edit: reading from the internet it seems my childhood was a lie...

Not really, it's just a word we use because it makes sense to us

Combustion is a decomposition chemical reaction where a more complex or larger molecule is broken apart into smaller molecules.

Nuclear Fusion is a reaction where intense force or pressure causes atomic nuclei to combine into heavier elements.

Stars are mostly hydrogen or other light elements. At the temperature of a star, most molecules that can combust can't actually exist.

Not only that, stars consist almost entirely of plasma, which is beyond the concept of combustion. Matter in a plasma state isn't changing like matter when it combusts, and as long as it remains at the temperature, it will remain plasma. Combustion will eventually run out of fuel and no matter how hot you get it, that same combustion reaction is over.

Stars don't burn and they don't have fire. They fuse and they are made of plasma

And yes I'm being a nerd about this.