Wastewalker Shu is the Dread Wastes Grand Master, he can be found at 55,37. His 3 pets are Crusher, Pounder, and Mutilate. You dont have to switch pets for all the rounds, you can ride the bird till it dies, then move into the Sea Pony. The Kunlai-Runt is last as this same team is very effective against Zusshi as well, you just start with the Sea Pony instead of the Raven on Zusshi. Here we open with the Raven.
Crusher is Aquatic, which roughly translates into "Please lord just kill me now!" I guess he just doesnt know how hungry my Ravens are. Because hes about to become crab salad. Round one opens with classic raven combo Darkness, followed by nocturnal strike. alpha strike spam and crusher wont be in the sequel.
Pounder is an elemental, and hes what I Like to use my elemental destoryer on, Sea Pony. He opens with sandstorm, which doesnt make any sense because it actualy helps your team survive when he does his AOE damage, so just drop whirlpool on him. Next round he will usualy use Rupture. It hits pretty hard, return with Water Jet. Now if your getting low on health, the whirlpool should have resolved by now , and just spam surge, it should kill him quickly.
Mutilator is a beast, and fairly easy to kill. he will generaly start with Spiked Skin, giving us a free round to set up. IF the ponys out hit whirlpool, then spam surge til its dead. IF the birds free use darknes and nocturnal strike and alpha spam, if everyones down, just Rampage zurg with the Kunlai -Runt. You can level off this boss with the Sea Pony and the Raven, you just have to find the timing to swap the level pet in, I generaly do it on the first round mutilator.