The Firelink Shrine bonfire can be upgraded to improve the amount of healing per Estus Flask use. These upgrades require finding Undead Bone Shards. There are 10 Undead Bone Shards that can be found throughout the world. Once you upgrade the Firelink Shrine bonfire to 11 (resulting in Estus Flask +10), the achievement will pop.


1) The first Undead Bone Shard can be found in the graveyard area just beyond the Dilapidated Bridge bonfire in the Undead Settlement. As you go through a small stone arch, you'll be pummeled with huge arrows by a giant high in a tower (unless, of course, you met with him and became his friend first). The shard is on a platform on the right hand side:



2) This shard can be found behind a gravestone overhanging a cliff in the graveyard area on the way to the Cathedral of the Deep:

Sorry, this Game Clip has been removed


3) From the Keep Ruins bonfire in Farros Keep, proceed away from the three enemies and look for a tower close by with several slugs inside. The shard is visible on a corpse inside this tower:



4) In the Catacombs of Carthus (proceeding from the Abyss Watchers bonfire), you'll come to a sloped path where a large skeleton ball rolls back and forth. If you kill the skeleton wearing the black witch hat near the bottom, the skeleton ball will break after hitting the lower wall and the shard will fall out:



5) From the Church of Yorshka bonfire In Irithyll of the Boreal Valley, exit to a graveyard and follow the path around to the right to find a large tombstone. The shard is behind it:



6) From the Demon Ruin's bonfire in the Catacombs of Carthus, follow the path to reach a large, two level room full of enemies. The shard is on the lower level in a corner:



7) This shard is in plain sight next to the Profaned Capital bonfire in Irithyll Dungeon:



8) From the Dragon Barracks bonfire in Lothric Castle, go across the bridge and drop down to find the shard beneath (in my clip, I'm already on the opposite side of the bridge from the bonfire):



9) This shard is on a corpse in a chair high atop the Grand Archives in Lothric Castle:



10) This shard is obtained by killing the giant worm in the Smouldering Lake area of the Catacombs of Carthus (near the Demon Ruins bonfire):