The roachs of arena:Mother talzian and Enfys nest/pest

Use rex with a pretaunter and toons that hit hard.

This way, assaj uses his dispel first turn. Then generally rex can go first and tenacity up unless they have spirit(not many do).
Point is, after assaj's dispel is outta the way, and you have tenacity up, you will always win unless your gear levels are too low.
Ten up prevents plague FYI.