Create a loadout that has snake pit II or III in it (probably less if you have two tanks to heal) and practice nailing your stuns. If you stay grouped and land a stun, evie will get deleted. Try to stun her right as she comes out of ice block.

It's tempting to get deft hands when you know you'll have difficulty with flanks, but you should get your reload speed from your loadout instead. This will allow you to get cauterize so you can keep down the enemy frontline and help your tank further