So I've played about every army against players that know the army and know how to use them all except The Sisters of battle. Not because there isn't an army around, cause he lives down the stairs from me but because the player is a

cheater and doesnt know the game rules or his own codex after 4 years of playing. A) In a 500 point tournament he organized for a small group of us he has a pretty strong army that had a Canoness with inferno pistol power weapon and Cloak of
St. Aspire. An Callidus Assassin. Two units of of Battle sisters each with 11 models 1 Veteran Sister Superior with a plasma pistol and two melta guns. and a Exorcist. It seemed like a solid list to me and just thought me stretched his points and had practiced like the rest of us but that army actually comes to 685 points. Also you can't even bring an assassin without an inquisitor in your army.
So after my bitching what my question is what are some effective ways to fight the sisters of battle? I was hoping to get response from both Space wolves and a Witchhunter player.
Much thanks