Does anyone know how to get the achievement? I see that people have obtained it but I just don't know what it wants me to do.

Whose bright idea was it to make the giant hands one shot you and be nearly undodgeable. And it's a pain in the rear to practice dodging them because you have to go through the parts of the fight before that every time.

Title. It's the only ending I'm missing now.

Can I get the others on this playthrough or do I need to start a new game?

At this point I'm starting to think that I either did something weird to skip this, or it's tied to difficulty settings above normal. For reference, I did unlock all 5 endings already. I also closed all distortions that are visible on the map . So I'm not sure how to get this one, looking at the global unlock rate, it feels like I should have gotten this long time ago....