This trophy hasn't changed from the PS3 version of the game even though the original DLC area is included in the remaster. I expected to have to get tail cut weapons and create boss soul weapons from the original game's DLC content, but you don't have to. You just need the original base game's "rare" weapons which I will describe in detail below.
Note that this trophy will require you to play about halfway into the third playthrough as you need three Soul of Sif and access to the Giant Blacksmith in Anor Londo.
Rare weapons fall into a few categories:
Weapons found in static locationsDragon Crest Shield- found on a corpse near the Undead Dragon in Valley of Drakes
Astora's Straight Sword- found on a corpse near the Undead Dragon in Valley of Drakes
Havel's Greatshield- found in a chest in a room behind an illusory wall in Anor Londo
Dragon Tooth- found in a chest in a room behind an illusory wall in Anor Londo
Dragonslayer Greatbow- found on a corpse in Anor Londo by dropping through a broken glass window in the entrance hall leading to Dragon Slayer Ornstein & Executioner Smough
Black Iron Greatshield- found on a corpse next to the painting in Anor Londo that leads to the Painted World of Ariamis
Velka's Rapier- found on a corpse in Painted World of Ariamis after the Annex Key door
Bloodshield- found on a corpse near the Undead Dragon in Painted World of Ariamis
Effigy Shield- found on a corpse in Tomb of the Giants
Weapons dropped by specific enemiesSome of these weapons are guaranteed drops and some are random drops. You likely will need to farm the appropriate enemies to get all of these weapons.
Increasing your item discovery can help get the weapons to drop more frequently. Consider using the Covetous Gold Serpent ring or the Symbol of Avarice (which do not stack) and having humanity in your counter to increase item discovery.
Black Knight Sword- dropped by sword-wielding Black Knights in Undead Burg, Undead Asylum (second visit), and Kiln of the First Flame (respawning)
Black Knight Greatsword- dropped by greatsword-wielding Black Knights in Undead Parish and Kiln of the First Flame (respawning)
Black Knight Greataxe- dropped by greataxe-wielding Black Knights in The Catacombs and Kiln of the First Flame (respawning)
Black Knight Halberd- dropped by halberd-wielding Black Knights in Darkroot Basin, Tomb of the Giants and Kiln of the First Flame (respawning)
Black Knight Shield- dropped by any Black Knight
Channeler's Trident- dropped by Channelers in the Undead Parish, Depths, and the Duke's Archives (respawning)
Crescent Axe- 100% drop by Patches in The Catacombs, Tomb of the Giants, or Firelink Shrine; sold by Patches upon relocating to Firelink Shrine for 10,000 souls
Crest Shield- 100% drop by Oscar, Knight of Astora in Undead Asylum (return visit).
Demon's Catalyst- 100% drop by Demon Firesage in Demon Ruins
Giant's Halberd- dropped by Sentinels in daylight Anor Londo; sold by Giant Blacksmith for 5,000 souls
Giant's Shield- dropped by Sentinels in daylight Anor Londo; sold by Giant Blacksmith for 10,000 souls (this may not be needed for the achievement)
Izalith Catalyst- 100% drop by Daughter of Chaos in Lost Izalith
Silver Knight Straight Sword- dropped by sword-wielding Silver Knights in Anor Londo
Silver Knight Spear- dropped by spear-wielding Silver Knights in Anor Londo
Silver Knight Shield- dropped by Silver Knights in Anor Londo
Stone Greatsword- dropped by Giant Stone Knights in Darkroot Garden; sold by Shiva of the East for 15,000 souls
Stone Greatshield- dropped by Giant Stone Knights in Darkroot Garden
Grant- 100% drop by Black Phantom Paladin Leeroy in Tomb of the Giants
Sanctus- 100% drop by Black Phantom Paladin Leeroy in Tomb of the Giants
Weapons obtained by joining covenantsGravelord Sword- join the Gravelord Servant covenant
Dark Hand- join the Darkwraith covenant; also a rare drop by Darkwraiths enemies
Weapons created from boss soulsThese weapons can be created by the Giant Blacksmith in Anor Londo and require having the appropriate boss soul and an eligible weapon upgraded to +10
Moonlight Butterfly Horn: requires Soul of the Moonlight Butterfly and any +10 spear or thrusting sword
Crystal Ring Shield: requires Soul of the Moonlight Butterfly and any +10 shield
Quelaag's Furysword: requires Soul of Quelaag and any +10 curved sword
Chaos Blade: requires Soul of Quelaag and any +10 katana
Greatsword of Artorias (Cursed): requires Soul of Sif and any +10 dagger, greatsword, or straight sword
other than Broken Straight Sword and Straight Sword Hilt
Greatsword of Artorias: requires Soul of Sif and a +10 Broken Straight Sword or Straight Sword Hilt
Greatshield of Artorias: requires Soul of Sif and any +10 shield
Golem Axe: requires Core of an Iron Golem and any +10 axe
Dragon Bone Fist: requires Core of an Iron Golem and any +10 fist weapon
Lifehunt Scythe: requires Soul of Priscilla and any +10 halberd or whip
Dragonslayer Spear: requires Soul of Ornstein and any +10 spears or thrusting swords
Smough's Hammer: requires Soul of Smough and any +10 hammers or great hammer
Darkmoon Bow: requires Soul of Gwyndolin and any +10 bow
Tin Darkmoon Catalyst: requires Soul of Gwyndolin and any basic catalyst (catalysts don't upgrade)
Great Lord Greatsword: requires Soul of Gwyn, Lord of Cinder and any +10 dagger, greatsword, or straight sword
Weapons that are obtained by cutting specific enemy tails off:
Drake Sword from the Hellkite Dragon in the Undead Berg
Dragon King Greataxe from the Gaping Dragon in the Depths
Priscilla's Dagger from Crossbreed Priscilla in the Painted World of Ariamis
Moonlight Greatsword from Seath the Scaleless in the Crystal Cave
Dragon Greatsword from the Stone Dragon (actually an NPC) in Ash Lake
Gargoyle Tail Axe from the Bell Gargoyles in the Undead Parish or from non-respawing Gargoyles in Anor Londo (note that this is not the weapon they sometimes drop when killed)
As always, refer to
http://darksouls.wikidot.com/ for specific information relating to items or locations.
This page on the wiki provides full information for all the weapons needed for this achievement.