These are my pride and joy. I REALLY love how Noxen came out, and I love how cute Darkit is! Anyway, some of it's a little hard to see, but I think you can get the gist of it.

Pokedex entry for Darkit:
Darkit, Bell Fox Pokemon
Darkits are a bit skittish and occasionally vicious and are thus difficult to train. However, if you can earn their friendship, Darkits make very loyal and protective Pokemon. The bell it wears around its neck rings at a different tone than all other Darkits. They will often get together to harmonize their bells at night. Many people have heard their sounds at night and been scared, but some find the Darkit's songs to be soothing and helps them get to sleep.

Pokedex entry for Noxen:
Noxen, Dark Fox Pokemon
Noxen's fur may look scruffy on the outside, but scientists have confirmed that the fur ruffles when it's frightened. Thus, Noxen almost constantly feels threatened. This only makes a stronger impression on its owner, because Noxen is calm and collected despite great fear. Noxen makes a loyal and protective of its owner, but only if Noxen feels comforted by them. If Noxen does not trust its owner, then it will attempt to defend itself if the owner gets to close. Because of this often unprovoked viciousness, many people do not bother trying to train Noxen. Those who do will have a friend for life.

How to evolve a Noxen from a Darkit:
In order to gain a Noxen, you have to get Darkit up to level 40 in Turnback Cave. If you don't, then Darkit will only evolve after level 40 with a Dusk Stone. However, Noxen can only learn Night Cannon (120 attack, perfect accuracy, Dark type) at level 40. And no, you can't just get it back with a heart scale.