Go to Naphui Quarter and put hard mode on.

Equip the following;

Build: Glyph of Swiftness, Deadly Paradox, Shadow Form, Way of the Lotus, Golden Lotus Strike, Fox Fangs, Death Blossom, Radiation Field (Asuran skill) 
Weapons: Perma Staff and Zealous Daggers of enchanting
Attributes: 16 Shadow Arts, 12 Dagger Master, 3 Critical Strikes

Enter mission, go to the light orb to the right of the bell, up the ramp. Make sure you run away from combat in a safe area.

You can’t kill a star light and they can’t kill you so don’t bother. Your goal is to kill Star Blades and Star Sentinels. You can kill these guys so long as there are 2 Star Lights in the group (not just 1).

If you only want to get the celestial weapons then run around until you see a celestial weapon on one of the birds, it will drop roughly 85% of the time. If you want feathers, just kill as many birds as you can.

When using the attack skills, don’t target a Sentinel because they block with lightning reflex, so target a Blade and your area effects will kill the sentinel, if you time it right.

Be careful about your energy and make sure to have 30 energy when you need to Renew Shadow Form. Skills 4-8 note what they do and know how to maintain the energy with them.

A successful run with picking and choosing the right places takes about 15-20 minutes (because you won’t be able to kill all groups with too many lights) and in the 15-20 you usually get 3-4 gold and 120 feathers.

The profit per hour averages to 16k and 10 gold (the gold could be worth a lot if you’re lucky).

Good Luck, and be sure to tell us how you did.