Something that recently came to my attention:
As far as pokemon with alternate forms are concerned, you can use a different form of them provided that they are different stat-wise. EG: If Rotom-Wash dies, you can use Rotom-Cut since they have different typings and movepools. If Gastrodon-West dies, you cannot use Gastrodon-East since the difference between the forms is purely aesthetic. If Deo-S dies, you can use Deo-D since stat distribution is different. Feel free to use Basculin-Pin if Basculin-Normal dies.
Also, remember to send in logs of your match.