Here's an alternate strat for Wastewalker Shu
that is very
reliable for people who dislike RNG.
A Red Cricket
can solo this fight and is the heart of this strategy. It can use Cocoon Strike to block all Whirlpool damage, has a massive (over 500) point self heal, and Rupture will do less damage and cannot stun it because it is type Critter. A hard hitting mechanical, preferably Tranquil Mechanical Yeti
, is used to speed up the fight by switching in for the last pet and nuking it.
1: Red Cricket
[-] (1,2,1) (Skitter
, Cocoon Strike
, [ability]Nature's Touch[/ability])
2: Carry pet
3: Tranquil Mechanical Yeti
[-] (1,1,2) (Metal Fist
, Call Lightning
, Ion Cannon
- Skitter until 1 round remains on Whirlpool
- Cocoon Strike, then use Nature's Touch
- usual sequence: Skitter x3 > Cocoon > heal > Skitter x2
- Cocoon Strike priority: Whirlpool > Sandstorm > Rupture
- Skitter and Nature's Touch when needed
- usual sequence : Cocoon > heal > Skitter x3 > Cocoon > Skitter x2
- swap to carry pet 
- swap to Yeti
- Call Lightning, if it misses then Metal Fist
- Ion Cannon
 In 5.3, the Yeti was better for this fight than all other pets with Ion Cannon because Call Lightning was used to counter Sandstorm. Even if Call Lightning missed, it would change the weather from Sandstorm to Lightning Storm. That increased the damage of Ion Cannon and, more importantly, removed any chance for Ion Cannon to miss. In 5.4, as a result of the changes to Sandstorm, it hasn't been up when the Yeti swaps in; Pounder was not reapplying it before killed. That means you should probably be fine if you use something like a Darkmoon Tonk, Menagerie Custodian or Sunreaver Microsentry. If you do have a Yeti, there's no downside to using it and its possible that run of Skitter misses could allow Sandstorm to get reapplied. So use a Yeti if you have one.
 In 5.3, I averaged 20.35 turns over 20 kills with the fastest kill at 18 turns and the slowest at 24. The strategy should be a little faster in 5.4. Rupture can no longer stun a Critter and so we won't lose the odd round to that. The Sandstorm change means a few Skitters that could have missed will now hit and, more importantly, there should be less incoming damage which means fewer attempts that need to spend a round on a third heal.
 Mutilator always casts Spike Shield this turn so carry pet will take no damage. The Yeti's damage is so high its not worth wasting turns grinding the Cricket to death.
EDITED for 5.4 changes