Batman: Return to Arkham - Arkham Asylum

Corner takedowns also count as silent kills as long as they don't see you.

FUCK this shitty console. This glitched on me.
I kept replaying it like 50 times wondering am I even doing the achievement correctly or is it glitched? I had to check the achievement list THEN it popped.
Screw Xbox and their de-sync hiccups that cause achievement unlock issues.

Just as a quick question, is the difficulty of the challenged assigned to the saved data or does it have its own difficulty?

Ie would I have to go through the game on easy to set the enemies difficulty to easy on challenges?

Oh, that’s a good question. I am honest: I don’t know for sure. It’s been too long since I played the game. Sorry. If somebody finds anything out please let me know.

Video is private now, so useless solution!

This is two years later and I assume OP got their answer already, but if anyone else is wondering, I believe that challenges have their own difficulty. I haven't done Predator challenges yet, but I just did the Combat challenges after doing the campaign on Hard, and the combat seemed like it was a lower difficulty (I got the alerts for when to counter which I didn't get in the campaign during fights due to the difficulty setting).