The stock spark plugs on the Evo X can fail as seen below from our 2014 Evo MR shop vehicle. The car currently has about 1400 miles.
The symptoms of this issue were that the car ran very poorly, had knock, and had a cylinder misfire. As you can see in the pictures the porcelain insulator will slide down and is no longer connected properly.
NGK claims it is from over-torquing the plug. The FSM calls for 13ft/lbs.