Within Their Grasp is a Atlas notable passive skill. Mastery: Breach.
PoE 3.21: The Within Their Grasp Notable Atlas Passive no longer provides chances for Breachstones dropped by Breach Bosses in your Maps to be Charged, Enriched or Pure. Instead, it now causes Breachstones dropped by Breach Bosses in your Maps to have a 5% chance to be Flawless. It also now causes Breach Bosses Defeated in your Maps to have 4% chance to drop a Breachstone (previously 12%).