User blog comment:ForgoxGamertag/Relian - The Spirit of the Strength/@comment-24170465-20140121020342/@comment-7888830-20140121111852

The charges are earned upon absorbing damage. However, it is true that the damage is slightly high, because, a lvl 18 charged E would dealt more than 700 dmg, which is excessive for a tank. I'll rework that, thanks!