non effective STAB megahorn (which you can further boost with swords dance) 180/2= 90 base power from 135 base attack stat his attack stat is mostly inverted and have a chance to be boosted to 180 power again
85 accuracy is more than acceptable (8.5/10 chance to hit).
turn 1: you switch in excavalier in choiced latios with draco meteor (or what ever)
turn 2: they switch to volcarona then you swords dance
turn 3: they use quiver dance cause it sounds stupid that you will stay then you KO with megahorn.. (and if there is stealth rock better)
iin conclution special=useless