This guide will walk you through the entire process of getting the Exotic swords in Destiny. Complete all of these steps to get the Raze-Lighter, Dark Drinker, or Bolt Caster.
Complete the quest, A Broken Will
Before you even sniff an exotic sword, you must get your hands on a Legendary one, by completing the Quest, "A Broken Will". Once you beat the Taken King main story, Shaxx will offer this quest, and requires gathering a ton of Hadium Flakes. These can only be obtained on the Dreadnaught, and requires farming runs that consist of running in circles over and over again. The easiest place to do so is in the Mausoleum, the area you reach after getting through the Cabal ship. If you travel counter clockwise around this area and enter all of the side rooms, you should be able to gather the hadium flakes rather quickly. Here is our full guide to farming Hadium Flakes!
After you have your hadium flakes, you must also gather 10 motes of light, and a corresponding element for whatever sword you choose. You can go farm these elements from the planets they are on, or buy them with legendary marks at the Vanguard Quartermaster. It requires 25 of either one. Talk to Lord Shaxx, and he will make you a shiny new blade. Upgrade it fully and above LL 280 by infusing, and then Shaxx will offer the Exotic quest, A Sword Reforged.
A Sword Reforged - Honing the Edge
This step of the quest requires you to test out the sword by getting 50 major kills, and 25 Guardian kills in the crucible. If you are having trouble with the second part, know that the sword still does damage, even without ammo. It does 122 per hit, the same as a melee attack, and the kills count, regardless of whether the sword is charged or not. Once completed, get back to Shaxx.
A Sword Reforged - Blade of Night
This requires you to track down Ecthar, Sword of Oryx in the Asylum. Jump into a Dreadnaught patrol, and head over to the founts. That means going through the Cabal ship and heading to the left most door that leads to the Sunless Cell. Fight through all of the enemies in the center room till you encounter the Warden Knights that have different elemental shields and take them down. Then get into the Asylum and wipe everyone till Ecthar rushes in.
He can only be hurt by your sword, so make sure you have heavy ammo, and don't forget to parry his attacks. After he is dead, get back to Shaxx once more.
A Sword Reforged - Essential Elements
This is a gathering materials step, and depends on what sword you chose. Solar requires Helium Filaments (The Moon). Spinmetal for Arc (The Cosmodrome), and Relic Iron for the Void Sword (Mars). Head down to the proper patrol, and farm these raw elements, as chests don't work. That means you should grab a ghost that identifies the material you are looking for, and prepare to do laps. You will need to gather between 100-120 materials to get the necessary rare versions. Once you are done, get back to Shaxx with what you have gathered.
A Sword Reforged - Armsday Alloys
Now we wait. We need a specific alloy from Cassoid Foundry, and we have to wait till the next Armsday refresh to get our hands on it. This happens on Wednesdays. After it arrives, gather from the Gunsmith, and talk to Shaxx.
A Sword Reforged - Sealing the Blade
You're going to want to be at Light 30 before you even consider this battle. Once you're set, go into the Sunless Cell Strike, and have at least three Guardians on hand. Trying this on your own is practically suicide. Make sure each Guardian has a unique type of elemental damage, so they can deal with the many shielded enemies that pop up.
You'll see Alak-Hul pop up alongside three Knights, known as the Wardens of Oryx. Assign your Guardians to similar shield types as the sword you're carrying, like with the Void Sword against Heolstor, Warden of Oryx, and so forth.
Go ahead and lay into Darkblade until you bring down its health to around five to ten percent, and make sure you repeat the process for the Warden of Oryx that coordinates with your sword type. Once you get both as close to death as you can, use the fireteam to let loose with their super abilities to finish them off for good. The Warden of Oryx should be killed first, then Alak-Hul.
A Sword Reforged - A Blade Reborn
Once that's done, return to the Tower and have a chat with Lord Shaxx again. He'll have your 310 Exotic Sword ready for use. You'll want to make sure you level it up right away for its special attack, using whatever Motes of Light that you have on hand. This will wipe out most enemies with yellow health bars with ease, and do damage to stronger enemies as well.