Both of these shadows wear very differently when wet compared to when they are used dry - lots of people who post negative reviews of the dark Night Series shadows do so because they don't realise how much more pigmented and awesome they are when used with a damp brush (or finger). Additionally, they look totally different in the pan. When swatched wet, Porter becomes much more opaque and the green stands out more clearly against the black base. Flight is super opaque when wet, and the blue is a little more obvious but it stands out best with flash.
Top to bottom: Bonus! NARS Ondine, dry then wet (don't bother wetting this one, it goes patchy), Night Porter, dry then wet, Night Flight, dry then wet.
Used wet in conjunction with a primer they make good eyeliners. I use a little freebie Urban Decay liner brush and Urban Decay Primer Potion, which was the best primer on the market when I first bought it about 6 years ago, but the primer market has boomed in recent years and there are probably others worth trying. Temptalia uses NARS primer, so that's probably a good recommendation.
I'm not quite sure what market these shadows are aimed at as they seem to fill no particular role in an eyeshadow arsenal, but I enjoy using them on the rare occasion I attempt a bold smoky eye.