How do you emotionally justify deeply intense fics?

Asking genuinely. I'd had some ideas for more intense fics that I think would fit a universe & evil characters well, and play on dynamics I've not seen others cover.

But it would also probably very NSFW at points, and would feel fucking sadistic to me at others. I like to be somewhat careful what I put out into the world, and I'm not sure deeply evil smut passes the bar.

But, I know some people do write stuff like that. And it would also fit the characters so well!! AND I've not seen others play into that dynamic!! Ugh. I'm so fucking torn. I've been toying with the idea for months and don't know if I can justify writing it when it'll be upsetting. (and toning it down would feel a bit like a character betrayal to some extent)

I will not be relying solely on this post to decide, I need to work out my own thoughts and opinions more (obviously). But to ask. How do you get through justifying emotionally heartbreaking/intense fics? Is it just something you enjoy, do you do it for the characters, etc? Is there anything you refuse to write- and if you're comfortable sharing, why? No judgement here. I'm just curious what the mindset tends to be.

Thank you for your guidance.