Glyph of Concentration

Acquisition
Skill Trainers: Signet of Capture:
 * Steig (Camp Rankor)
 * Dakk (Ember Light Camp)
 * Whiskar Featherstorm (Borlis Pass (Mission), Griffon's Mouth)

Note
The skill appears to be bugged, as it is sometimes still possible to be interrupted by Destroyer of Deeds using Broad Head Arrow in Glint's Challenge, even while the effects of the glyph are still on you.

Related articles

 * Glyph skills quick reference
 * Prevent interrupt skills quick reference