Warhammer Age of Sigmar: Storm Ground
43 Achievements
PS4
Battle Master
Equip a skill on a unit for the 1st time
74.9%
How to unlock the Battle Master achievement in Warhammer Age of Sigmar: Storm Ground - Definitive Guide
When a unit levels up, they receive a skill slot. In the warband screen, choose a unit then press RB to go to the skill screen, then add one in. I used the Bleed skill on my Castigators. The game will pretty much guide you to this achievement.