Commander Durand’s “Flash of Steel” ability might be scaling a bit to high for the level the encounter can be fought at. Leveling a zandalari for the heritage armor and in the blink of an eye he one shot me, three back to back hits of almost 350 damage a piece before I had a chance to react with either a heal or a defensive. For reference at lvl15 I have 846 hp.
He also one shot two of the group members in the same manner, Flash of Steel targeting them multiple times in a row and just turning them into a fine red mist.
https://imgur.com/a/T6Z65eS