Pursuit nails offensive Pokemon switching out, often OHKOing MMX and Mega Rayquaza from full if they switch out. I chose to run Knock Off over Sucker Punch because the latter felt redundant with Water Shuriken (though, of course, it's still a great option) and running it meant Gyarados ...
Primal Groudon, Mega Rayquaza, and MMX are the big ones here; Groudon can switch in multiple times per battle due to its bulk and immediate power, Rayquaza is unpredictable due to the prevalence of both physical and special sets, and Choice Band MMX, with support, can break through Giratina...