Shatter is a threshold Constitution ability, unlockable through Raids from either the untradeable Storm Shards and Shatter Ability Codex, or the tradeable Mazcab ability codex. It is unlocked with the Storm Shards ability. When Shatter is cast after Storm Shards, all stacked up damage is applied in one go, and will deal damage up to a maximum of 30,000 life points. It works in PvP, although the use of Freedom will halve the damage caused. If Shatter is used upon a target with no storm shard stacks, adrenaline will be lost but the ability will not initiate cooldown.
Under most circumstances, you will hit 30,000 damage when you have 10 stacks of the Storm Shards ability applied on an enemy while under a damage-boosting ultimate ability.