@Johnny That's like saying Gengar beats Tyranitar because it can run Will-O-Wisp or Focus Blast.
Basically you have two options: switch or stay in. If you switch you either die to pursuit or your switch-in will have to take a STAB SE or Crunch to the face. If you stay in, you either die to SE or Crunch or you manage to burn T-tar after taking massive damage from Pursuit. So 50% you die, 25% one of your mons takes a hit from a T-tar to the face, 25% you successfully render T-Tar useless, in exchange for probably being revenged.
@Butterfree Those are not counters, they are checks at best.
1. You can switch out of Heatran who fails to nab a Flash Fire, because you can't switch in on Shanderaa.
2. Sure there are pokes with Aqua Jet, what is keeping you from switching out to something like Suicune? And by this logic Mence is rendered useless by Ice Shard, which we know is not true.
3. Why exactly would anyone switch their Shand in on yours. Like you said it's a speed tie, so 50% they win, 50% they just lost a major team member for no reason.
4. Nothing new here, just Wobbuffet doing its job (?)
5. So you switch out to come back later.
6. I don't get it, if you mean SR helps pokemon by turning 2HKOs into OHKOs the exact same can be said of any offensive pokemon, including Shand.
7. Shanderaa doesn't really care about being burned, and why is it staying in on a water type?
8. I was just saying that T-tar was a good revenger for Shand, here you're just supporting my point.
9. Again supporting my point. Pursuiters can reliably kill Shanderaa.