The Firesage Skip is a skip in Dark Souls found in January 2015 by Distortion2. It enables the player to skip from after the Ceaseless Skip to the Centipede fight, and from there its possible to engage Bed of Chaos. This skips the need to visit Blighttown and Quelaag's Domain twice, saving potentially up to 3 minutes.
Before the Golden Fog Gate, there is a Rock Worm on the right side after walking down the long stairway. Stand between it and the wall behind it and execute a frame-perfect R1 attack with the BKH during the grab attack to fall under the map. You should land on the ceiling of the Centipede area, where you can heal, and from there you can drop further into the boss battle.
- Demonstration by Distortion2 on Twitch