There are six legendary Ashen Remains which count towards the Legendary Ashen Remains achievement. This page details how and where to find each of them to unlock the achievement.
Where to Find All Legendary Spirit Ashes
Lhutel the Headless
The Lhutel the Headless spirit ashes are dropped by the Cemetery Shade (Weeping Peninsula), located in Tombsward Catacombs in western Weeping Peninsula. From the locked doors leading to the boss room, turn right and follow the path down the stairs to the south. Turn left down the eastern path from this room and follow it to the end where you’ll encounter a fire breathing statue. Wait for the fire to disperse, then quickly run into the hallway and turn right into the small space before the fire erupts again. Once the fire is dispersed a second time, continue south towards the statue and hit it to stop the fire breathing, while also causing it to drop into the ground. Hit it again and quickly leap onto the platform at the top of the statue, as it takes you up to another set of rooms to the west.
Follow the path westward from here until you see a hallway to the north with a statue and a lever at the end of it. Pull the lever before jumping down and heading up the stairs to the north, taking you back to the boss room doors, which are now open. After you defeat the Cemetery Shade here, you’ll acquire the Lhutel the Headless ashes as a reward.
Redmane Knight Ogha
The Redmane Knight Ogha Ashes are dropped by the Putrid Tree Spirit, located in the War-Dead Catacombs in eastern Caelid. You’ll need to defeat Starscourge Radahn before you can access this area. To reach the Putrid Tree Spirit, head west down the hallway from the first set of steps in the catacombs, ignoring the fighting soldiers as you make your way up the stairs to the north of them. Follow the ledge at the top of the stairs eastward, then turn north to find more soldiers. Be wary of the soldier at the end of this hall, who wields a powerful bow. Take the path east from this enemy and follow it as it bends south. From here, turn right through a small archway to the west, which you’ll need to jump through to enter the room below.
From this room, head south up the stairs and then head through another small archway to the west, where another soldier with a bow is taking aim. Beyond this archway you’ll find a lever that you need to pull, then head west down the stairs beyond the fighting soldiers, leading to the boss room where the Putrid Tree Spirit dwells.
Mimic Tear Ashes
The Mimic Tear Ashes can be found in Nokron, Eternal City. You’ll need to defeat Starscourge Radahn before you can reach this area. The easiest way to reach this area is by heading northwest from the Fort Haight West Site of Grace, in southeastern Limgrave. Here you’ll find an enormous hole in the ground which leads to Nokron, with rocks suspended in the air above it. Make your way down to the bottom until you reach the city, then head north across the rooftops. You’ll soon reach a ledge with a large open window to the northwest. Go through this and then jump down onto the platform below, heading northeast through a door to a Site of Grace. Turn northeast from here to enter a courtyard, then take the path down a narrow set of stairs to the east, bringing you to a bridge which leads to a boss room to the southeast.
You’ll find the Mimic Tear boss in this area, and once you’ve defeated them the path to the northeast will open to you. Head up the stairs and over the bridge until you see a path below it (to the west) with an obelisk next to it. Head directly west from the obelisk as you bend up the hill southward, where you’ll find another Site of Grace. Jump on to the rooftops to the southwest from here, then drop down to the ledge beneath this first roof as you turn west, entering Night’s Sacred Ground. Continue jumping down to the dome roof towards the southwest, then jump from this to the platform south of you. Follow this southeast as you come to another rooftop ledge, and jump down from here onto a broken stone structure, which leads into a cathedral.
Once you’re inside the cathedral, continue southeast until you see an imp statue. Use two Stonesword Keys to open the room beyond, where you’ll find the Mimic Tear Ashes in an ornate chest.
Ancient Dragon Knight Kristoff
The Ancient Dragon Knight Kristoff Ashes are dropped by the Ancient Hero of Zamor (Sainted Hero’s Grave), who can be found at the end of Sainted Hero’s Grave in central Altus Plateau. After taking the elevator down into the main part of the grave, head south into the room with the Site of Grace and then take the eastern path down. Take your first right down the stairs to the south and then your first left to the east again. Continue down two sets of stairs and through the archway directly ahead, turning left down more stairs to the north. You can jump onto the depressed surface in the centre of this room, causing the floor to crumble as you fall through it. There are a number of imps in this room that you’ll need to deal with, so be prepared for a potentially messy fight.
Once all the imps are dead, use the lever on the northern side of the room to open the gate, leading to a path with some blade traps. Run beyond these as you turn east to another set of blade traps, then take your first right through the archway to the south, where you’ll find a ladder leading up. At the top of the ladder you can jump off the ledge and head west up the stairs to a duellist enemy. Defeat the duellist and then head back to the room where the blades are. You can now go through the open door to the east to find the boss room.
Cleanrot Knight Finlay
The Cleanrot Knight Finlay Ashes can be found in Elphael, Brace of the Haligtree. From the Prayer Room Site of Grace, head north and follow the path down the steps until you reach a corpse lying over the edge of the balcony. Jump down to the northwest from here and turn left into a room with a chest, guarded by Cleanrot Knight Finlay. Kill the knight and then loot the chest to find the ashes within.
Black Knife Tiche
The Black Knife Tiche Ashes are dropped by Alecto, Black Knife Ringleader, who can be found at the Ringleader’s Evergaol in southwest Liurnia of the Lakes. You’ll need to pursue the Age of the Stars ending to reach this part of the region. To reach the Ringleader’s Evergaol, you will need to travel northwest from the Moonlight Altar Site of Grace, likely found during Ranni’s questline.
Once you’ve acquired all six of these legendary spirit ashes, you’ll unlock the Legendary Ashen Remains achievement / trophy.