It's also used as a joke one, too, if you're not uptight about it. I think it's a silly icon with a silly phrase that it would be silly for Bullseye to actually say, because it's a teen girl thing to say matched with a cold, hardened assassin dude. It's already out of context.
If the person I responded to (which is not you) is genuinely upset by it, I'd just give 'em a genuine "my bad," because I was just being silly and thought that'd come across, and if the mods deigned to give me a strike over it, I wouldn't argue it.
But part of a personal insult is intent. There was none on my end to actually insult the other poster. I thought the icon was silly, and that any silliness would come across. Apparently, it didn't. All I can do there is go "whoops" and clarify that I thought it was just silly. Which I have done.
So chill. You're not fighting a huge injustice here. You're fighting "someone thought an icon was silly enough to not be taken seriously and didn't take into account someone else would interpret it seriously."
And honestly, you're doing the thing that makes me have the hugest problem I do with this place, and why I only just rejoined, like, today. I'm all for holding people accountable to their words, and anti-racist, anti-misogynist, anti-ableist language and all that, but there's a point where people cross over into ignoring the intent of the poster and the fact that sometimes they don't communicate things well or a joke goes off its mark rather than them intending ill will.
Chill. I'll be more careful next time. Though, honestly, the easiest way to settle this was simply explaining it wasn't a real insult and that I meant it like "Blasphemer", which I already did, and would've done if the poster went "Hey!"