Scourge of the Corruptor to quickly kill the first couple of waves till Mourning Wood comes, then use the Vampire Knives against M.W. When Pumpking Arrives, keep using the V.K. and use the S.C. on minor enemies and against M.W. if you are good at Dodging. All accessories should have the modifier that increases melee speed up 4%. Armor should either be Dragon Armor, Hallowed Armor (Melee set) or the Chlorophyte Armor. Also have the Flask of Ichor or Cursed Flames. Get the best modifier for S.C. and V.K. The arena should be open and lay the ground with Asphalt Blocks to dodge when necessary. Also drink an Iron Skin Potion, Swiftness Potion and a Featherfall Potion for Pumpking. And thats it i guess