Ah shit, I didn't realise. Still. He could be the older brother she never had. I'm keen on the idea that Sombra always flirted with illegal shit (gangs drugs some light hacking etc), as opposed to being knee deep in it like she is in canon. I've found the app on your journal and would this be something that Reyes was possibly involved in while was still active?

Alternatively, depending on how your timings worked out he could have been Sombra's home ec teacher and always had an eye out for her.