252 Atk Life Orb Mienshao Aerial Ace vs. 252 HP / 0- Def Abomasnow: 234-278 (60.9 - 72.3%) -- guaranteed 2HKO
252 Atk Mienshao Acrobatics (110 BP) vs. 252 HP / 0- Def Abomasnow: 330-390 (85.9 - 101.5%) -- 12.5% chance to OHKO
252 Atk Life Orb Mienshao Aerial Ace vs. 252 HP / 0 Def Mega Venusaur: 140-166 (38.4 - 45.6%) -- guaranteed 3HKO
252 Atk Mienshao Acrobatics (110 BP) vs. 252 HP / 0 Def Mega Venusaur: 196-232 (53.8 - 63.7%) -- guaranteed 2HKO
252 Atk Choice Band Mienshao Aerial Ace vs. 252 HP / 0 Def Mega Venusaur: 160-190 (43.9 - 52.1%) -- 17.6% chance to 2HKO
Running itemless Pokemon is a waste, imo. You will often find yourself not being knocked off and then you would have just wasted the opportunity to use an item.
Mienshao really likes Life Orb, and even Choice Band or Scarf are viable.
Erm. The part in bold is showing a 2HKO on, according to the calculator, standard usage MegaVenusaur, outdamaging both Life Orb and Band by a decent amount while itemless. Is there another move that can claim similar merit on Mienshao, because that's a pretty useful thing to hit that hard.
A scarfed set makes a wonderful revenge killer, I know. Band hits like a truck. Life Orb lets it dish out damage all over the place. But a 110 bp attack, in conjuntion with 156 from HJK, and stone edge and knock off, I think I will try some testing. It will probably be terrible. But no harm in testing, I hope.