Superior Sigil of Ruthlessness

Double-click to apply to a weapon. — In-game description

“

Double-click to apply to a weapon.

Gain 5 stacks of might for 10 seconds when interrupting a foe. (Cooldown: 3 Seconds)

— In-game description

Acquisition[edit]

Vendor	Area	Zone	Cost	Notes
Exalted Mastery Vendor	Noble Ledges Tarir, the Forgotten City	Verdant Brink Auric Basin	250 + 2	Requires the mastery Exalted Acceptance.
Heroics Notary		World vs. World	75 + 20	Requires Heart of Thorns and Provisions Master 6th tier.
Heroics Notary (item currently unavailable)		World vs. World	75 + 20	Requires Heart of Thorns and Provisions Master 6th tier.
Heroics Notary (item currently unavailable)		World vs. World	75 + 20	Requires Heart of Thorns and Provisions Master 6th tier.

Avoid Traps	Heart of Thorns: Act 2	5
Find Taimi without stepping on any Mordrem traps.Story Instance: "Strange Observations" Prerequisite: Strange Observations Reward: Superior Sigil of Ruthlessness	Found Taimi without Falling Victim to a Mordrem Ambush	5

Works on all bosses or any foe with a Defiance bar. See main paragraph on interrupt.

For a detailed rune history, see here.

Patch	Changes
November 13, 2018	Might now lasts for 10 seconds instead of 3 seconds, but has a 3 second cooldown after interrupting a foe.
December 12, 2017	Now works on any boss or foe with a break bar.
October 23, 2015	Heart of Thorns release: Superior Sigil of Ruthlessness has been added to the game.

Sigil of Ruthlessness