is this a real demon?

Once they changed the name you can see sales picked up.

Eh, not really. In '73 they sold 79,428 Dart Sports. Yeah, that was more than the 48,580 Demons they sold in '72 but it's still less than the 79,959 they sold in '71. And the numbers went down again from there. Meanwhile in '73 they sold 264,974 dusters. So the sales for the Dodge sport body were never close to the Duster, regardless of what they called it.

All the production numbers are here Production Figures