@paroton13 OK turns out one can complete the Night Watch quest by only wearing Noblesse Set, How?
I activated my Brain Prowess & realizes that equipping the Blinding Bullet can "Blind" the mobs so their attacks wont hit me that much cuz they couldn't see me as most of their attacks "Miss" now + tons of White Syrup & Blue Syrup in my RODex.
I literally saved tons of zeny not to buy expensive equipment just to finish this.

@Boyeteers Thank you for the suggestion, I really have no idea what that means at first as I'm too lazy to google & read. Until I accidentally clicked on that "Flame" beside the DK NPC & find out that you can just bribe the Valkyrie with Nyangvines for the instant job change. It only costs me 26m zeny for 100 Nyangvines.