Assault by Ground

Make sure to pick up Blood of the Chosen from Knight-Captain Drosche on the Skybreaker before you begin this escort, as the Ymirheim Defenders that spawn during the event all count toward the 20 kills you need for the other quest (as long as you contribute non-negligible DPS).

The squad leader will say "Alright boys, let's do this!"

At least I still have http://www.wowhead.com/?item=21028

You do not receive credit for Blood of the Chosen if you contribute little or no DPS during the fights. As a holy priest, I just kept all the NPCs healed and buffed; the quest was very easy this way, but I unwittingly realized later that this credits you none of the kills.