With Daki hearing the blood-inherited memories, I wonder if there in an innate fear across all the demons about Sun Breathing. She instinctually ripped off her own foot at the ankle to get away from Tanjiro after he caught her, even though she can probably easily beat him with her full power.

I guess it makes sense that Sun Breathing is equated fire that flows like water, plasma, whatever. It's more like Waterbreathing in style and motions, but manifests as fire. And it burns them much harsher. Also interesting in that it is depicted as cutting very effortlessly, but is leaving ragged cuts where it has gone through.

But I guess Sun Breathing is actually anaerobic at full speed? Tanjiro's little sister warning him to breathe, he finally did, and got a huge backlash. Had he been holding his breath in this whole time? Or maybe using it damages the lungs. That would make sense with their father.

Nezuko going to full Anego mode.