Use Tomusa's Hook on Triumph War Gryphons to dismount and kill 5 Wildhammer Mercenaries.
The Alliance has hired in Wildhammer mercenaries to control the skies over the Battlescar. I believe these same gryphon-riders were the ones to firebomb Taurajo during the attack.
I want our skies scoured clean.
The wildhammer dwarves fly low enough for a sharp-eyed <class> to hook them. Take this. Target their gryphons and dismount the riders - once grounded, show them no mercy.