Use an online pokédex, like Veekun, and look under "Base Stats". And, like the games, the substitute fades when it has taken more damage than its value. A 20% substitute will fade when it takes more than 20% combined damage. Weather effects and statuses don't count. And yes, the substitute is once.
We're having a PM conversation. If you are curious, then ask her.
We're having a PM conversation. If you are curious, then ask her.