In Heartgold, does Tyranitar get a special defense boost from it's own Sandstorm? Because mine keeps surviving focus blasts, which surprised me, and I figured thats what was going on. If so, that makes him a pretty good investment because it would really need no special defense EV training
Actually, Tyranitar did get a boost as a result of the sandstorm. Sandstorms are more beneficial to rock types more than steel or Ground types because Rock types get a 50% special defense boost for the duration of the sandstorm. That would explain why he could take a focus blast. This boost is as of Generation IV. My source is right here.