look at the weapons... I used some acrylic drying retardation medium (I was trying to get my paint to go on smoother - it did let me thin it and keep a good flow until it thinned even more on me) and had it mixed on my wet pallet. toward the end enough water soaked up and thinned it... and it ended up making what looks like contrast paint (now if they were only primed white and that was a color (so the black was white and the white was the color - I would have a really nice effect (or if I wanted that glowing black color for them).
Reaper is already pretty loaded with flow aid. So maybe just glazing medium with the reaper?
The team that makes reaper paints like to gloat about making their products stubborn and uncooperative, I found that out after the glaze medium basically destroyed three if their paints and I went to ask what gives in their forums. I won't be purchasing any more reaper paints in the future. At least vallejo apologized for the inconvenience.
I have a ton of Reaper paints from an estate sale and I agree that they're not my favorite. They're great for brush painting in a layering style and very little else. Getting through an airbrush is annoying, making them into a wash can be annoying. I'm going to keep using them up, but any new paints have been army painter (and those I squeeze out the extra medium they put on top and then add a glass bead as an agitator as they are very thick).
One thing I will say though, is that the Reaper paints last. I have some that were from their first batch of dropper bottles in like 2001 and they're working just find today.