All right, Diablero is not exactly a movie but a TV series on Netflix, but that doesn't make it any less reviewable. And it is definitely watchable.
I watched the dubbed version (because I was trying to get some writing done), and didn't feel too distracted. The voice actors did a descent job, though I have no basis to judge how good the translations were.
It's a classic ensemble urban fantasy, with a redemption story for the protagonist, a bad girl using her curse for the cause of good, monsters, bad guys, and a supernatural underground that exists outside yet part of normal society. The tropes are strong with this one, but it's not a painful cliche, and is still a fun ride to the end.
The last couple episodes are a little rushed, and the timeline is really off, but there are demon children. Definitely room for a second season, and I really hope there is one.