Here’s my strategy for Mr Shu, located just outside the Klaxx’i hub.
I used these pets, with abilities shown, to counter his pets, Crusher, Pounder and Mutilator.
Crusher came first and by using the Faerie Dragon’s Moonfire and Slicing Wind he was a gonner. With Pounder, I used Life Exchange then Slicing Wind til my Dragon was dead. Next, Pounder cast Sandstorm so I countered with Cleansing Rain on the Water Skimmer and used the other abilities til Pounder died.
Finally, Mutilator took out my poor Skimmer’s remaining health quickly, so I swapped to the Idol and punched him in the face til he died.
A relatively stress free fight with these pets. Good luck!