- One Bonfire Ascetic can be obtained if it is chosen as a starting gift.
- One can be found on a corpse in The Lost Bastille. On the level directly below where Straid of Olaphis is found, one must drop down the shaft of the cage elevator onto a narrow ledge below.
- One can be purchased from Stone Trader Chloanne either in Harvest Valley or Majula for 7,500 souls.
- One can be found at the start of Iron Keep, near the first bonfire, it can be seen from the broken section of the bridge. One must traverse several burning sections of rock to reach it.
- One can be found next to Cromwell in the church in Tseldora.
- Ten can be purchased from Darkdiver Grandahl as a part of the Pilgrims of Dark covenant for 7,500 souls each.
- Bonfire Ascetics may be farmed from the inhabitants of the Dark Chasm of Old, which costs one Human Effigy to enter and one must be a member of the Pilgrims of Dark covenant.
- After defeating the Looking Glass Knight, three can be found in a chest to the left of the path leading to the elevator that takes the Cursed Undead to the Shrine of Amana.
- One can be found in the Shrine of Amana, on the opposite side of the stairs where the Manslayer is found.
- Ten can be purchased from Royal Sorcerer Navlaan for 7,500 souls each.
When burned, a Bonfire Ascetic will change the entire bonfire area to the next playthrough level. For example, if used during the first playthrough, it will bump the difficulty to New Game+, and if used at New Game++, it will bump the difficulty to New Game+++. This process is irreversible and persists on following playthroughs. For example, if an area was increased to New Game+ on one's first playthrough, it will be at New Game++ difficulty on the next playthrough.
- Observed changes between NG and NG+ version of Things Betwixt so far were: stronger enemies with higher soul rewards; additional enemies (including Black Phantoms); different enemies (i.e. an archer upgraded to a crossbowman); different item locations; and different, often "upgraded" loot.
- Using the Bonfire Ascetic will reset the enemy spawn counters in the area, and most of the area's items will respawn.
- Items in metal chests do not respawn when an ascetic is used.
- This also applies to the dedicated bosses of areas (e.g. the Last Giant and the Pursuer at the Cardinal Tower). This is useful for soul farming, assuming one is capable of taking down these stronger bosses.
- Bonfire Ascetics can only be used if the area boss has been defeated. If no area boss exists (such as the Belfry Sol area), bonfire ascetics can be used repeatedly without needing to clear the area.
- Using a Bonfire Ascetic in an area that gets invaded frequently will, on a rare occasion, cause the process to be interrupted and the Bonfire Ascetic to be consumed, while not respawning the area around the bonfire it was being used on.