Here's how I painted the Night Lords lightning effect:
- First I painted a thinned color for an overall appearance of "electrical haze" or "glow." I used GW Enchanted Blue thinned down to a 1:4 paint/thinner consistency and applied this with a 2/0 brush so as it have a "backdrop" color to paint everything else on. I didn't want this to look solid (hence the translucent paint) but I did want it to serve as an overall "outline" for the two subsequent colors.
- Secondly I went back with thinned Electric Blue (in a 1:4 paint/thinner ratio again) - it's an old, old color so a good substitute would be 1:1 Enchanted Blue/Ice Blue, I dare say. With this step I used a fine (#0000) point brush and more or less stippled a random, crackling line within the previous haze color. I intentionally kept it patchy and wavy while still trying to follow a more or less continuous arcing path - the next and last color I would say is the most important, as it's the "heart" of the electrical effect.
- Lastly, I applied fine stippling with thinned GW Ice Blue (1:4 paint/thinner ratio again) and just tried to make it look like crackling electricity - I didn't necessarily keep to the exact center of the previous two colors laid down, but I didn't stray outside of them. I made a few passes with just tiny dots of the brush, until I got to the point where it looked like a fine (if fuzzy) line with a few patchy gaps here and there. Done!