ReiTuki likes to create custom mods for Second Life by patching together existing mods with a little custom work here and there. In this Krystal mod, the head was made custom, and combined with existing body and face mods to create one of the nicest Second Life Krystal mods I've ever seen, albeit a stylistic interpretation of her various facial features and body shape. Interesting staff and clothing too.
It certainly helps that ReiTuki is very good at taking photos of these creations. Have a look at ReiTuki's Flickr Gallery for more examples.