We’ll cover both methods for getting Greirat’s Ashes below, all step-by-step.
Method 1: Killing Greirat
The fastest way to get Greirat’s Ashes is by killing him towards the beginning of the game. If you use this method, you won’t miss out on much unless you’re an NPC quest completionist.
Freeing Greirat
Before you can kill Greirat, you’ll first have to free him from his cell in the High Wall of Lothric using a Cell Key that’s found elsewhere on the High Wall. Warp to the Tower on the Wall Bonfire to get started. From the Bonfire, walk down the steps and into the dark building below. Roll off of the broken floorboards to the floor below, then step outside onto the ramparts. Roll off of the small ledge in front of you, then sprint across the rooftop to avoid the horde of enemies. Roll off of the rooftop near the ladder for a safe landing to a balcony below. Next, head inside and follow this path down, taking out or running past the large Knight. Once you’re through the door behind the Knight, follow this wooden pathway down until you reach its end and momentarily step outside. Follow the stairs down and you’ll be back inside, in a large room packed with enemies. It’s in this room that the Cell Key can be found. You can either take out the enemies here one by one, or risk dying while making a mad dash to the Key. Regardless of which route you take, you can find the Key at the bottom of a set of steps in the back left corner of the room. Once you have the key, you can now free Greirat from his imprisonment. First, walk or warp back to the Tower on the Wall Bonfire to regain your healing. From the Bonfire, head back downstairs into the dark building, and roll off of the broken floorboards. Take out the enemies on this floor, then roll through one of the holes in the floor to drop down again. Take out the enemy on this new floor, then head through the stone archway. In this next corridor, there’ll be an enemy lying in ambush. Be sure to take it out or it will follow you and attempt to kill you as you speak to Greirat. At the end of this corridor, take out the Assassin to the left, then turn right and head down the stairs to find Greirat in a cell in the tower straight ahead. Use the Cell Key to unlock the door, and then talk to Greirat. You can kill him now and still get the Ashes, but they won’t unlock Lightning Urns if you get them this early. Instead, keep talking to him and agree with his request. Once his dialog is exhausted, he’ll then disappear, reappearing in Firelink Shrine. Warp back to Firelink, then head down the tunnel straight ahead. Once you reach the stone walkway in front of Andre, roll off of the left side to find Greirat.
Delivering Loretta’s Bone
To get Greirat’s Ashes to unlock Lightning Urns, you’ll first have to complete the first two steps of his questline. First, you’ll have to find a key item called Loretta’s Bone and deliver it to him. Warp to the Undead Settlement Bonfire to find it. Walk forward from the Bonfire and into the dark building ahead. Walk down the steps to reach the floor below, then walk out onto the balcony at the back of the building. Here you’ll see a hanging corpse that’s holding a glowing item. Hit it with any weapon and it’ll fall to the ground. Jump down onto the ground and pick up Loretta’s Bone from the corpse. Warp back to Firelink Shrine and give the Bone to Greirat to continue his quest.
Sending Greirat To Loot The Undead Settlement
Reset the area by warping away and back again, then exhaust Greirat’s dialog to send him on a quest to pilfer the Undead Settlement. Head back to the Undead Settlement yourself, and progress through the game until you reach the Road of Sacrifices. Head back to Firelink Shrine from the Road of Sacrifices and Greirat will have returned to the Shrine. You can now kill him, and his Ashes will now unlock Lightning Urns.
Method 2: Completing Greirat’s Quest
If you don’t have the heart to kill Greirat, you’ll have to complete his lengthy quest to get his Ashes. You must start this quest before reaching Irithyll for every step to work correctly. Here’s a quick rundown of all the steps in his quest: You can also find a full breakdown of Greirat’s questline on the Dark Souls 3 Wiki.
Buying & Farming Lightning Urns
With the Ashes collected, head over to the Shrine Handmaiden in the Firelink Shrine tunnel. Talk to her and choose to ‘Give umbral ash’, then select Greirat’s Ashes. Giving her these ashes will unlock various items in her shop, including an infinite supply of Lightning Urns.