Maybe Gardy ex!!
Hmm ariados, skarmory ex, doing damage until 50 hp is good but if he retreats :s.
Shiftry ex (cg) (ok stage 2) 50 hp if they retreat here comes shiftry.
I was also thinking about Blastiose D (weakness remove + gardy power puts 2 damage counters on a poké + engadge linar attack)