UPDATE: White Lily Collar
Fancy Fencing Rapier is a solo weapon and Scales itself with the help of Piercing Arrow. You need some time to ramp, therefore it's recommended to use double big shield in particular Moon Shield with double armors. Holy Armor is important to get White Lily Collars. They generate luck for ancy Fencing Rapier to Scale and you'll gain crit chance with Regen. Moon Shields can generate so much mana that
Make Fancy / Katana as fast as possible with the help of Fanny Packs, Gloves and Maneki-nekos.
Oil Lamp gives accuracy that Fancy hits more after ramping up.
Amulet of Energy is by far the best amulet but Amulet of Steel or Amulet of Fortune can be useful aswell.
Winged Boots, Cap of Discomfort, Stone Helm and Stone Boots are good defensive options.