My Timid Liepard with 30 IVs across the board (N's), with +2 in Special Attack thanks to Nasty Plot, having been EV trained, with Special Attack and Speed maxed out, failed to OHKO a Palkia with STAB Dark Pulse, back in that Rotation Battle tournament.
Now for one that was actually good on my end- on Random Matchup, I took out my opponent's Gyarados and Conkeldurr with a level 1 Cleffa.
Official badass Admin of Team Miror Infinity. I ride a Shadow Scolipede. Top that. I dare you.