Board Thread:New on Terraria Wiki/@comment-25753700-20141124015202/@comment-27560757-20160224015228

Pigman0439 wrote: I would recommend the Paladins Hammer, True Excalabur, Scourge Of The Corruptor and or the Rainbow Gun. Switch between using the Gun and Hammer or Excalabur. I took him out pretty easily with the Paladins Hammer.

(I would also recommend using Iron Skin, Thorns Potions and Normal or Greater Healing Potions. Hollowed, Turtle or Beetle Armor can be helpful)
 * Paladins Hammer: Dropped from killing Paladins in the Dungeon
 * True Excalabur: Crafted with 1 Excalabur and 1 Broken Hero Sword.
 * Rainbow Gun: Obtained from opening the Hollow Chest in the Dungeon, Hollow Key needed to open.
 * Scourge Of The Corruptor: Obtained from opening the Curruption Chest in the Dungeon, Corruption Key needed to open.

Hope this helps somewhat.

-Pigman

P.S. you can not get any of these items without beating the destroyer