I know this was already asked, bringing it back up with a bit more added on.
Add abilities like Levitate and Flash Fire. But if a Pokemon has multiple abilities with one of them giving a resistance or immunity, have that Pokemon be available on multiple spots. For example:
Not Very Effective: Heatran (Flash Fire)
Normal Effectiveness: Heatran (Flame Body)
Normal Effectiveness: Bronzong (Heatproof)
Super Effective: Bronzong (Levitate/Heavy Metal)
But no need to list abilities for a Pokemon without an immunity/resistance ability.
Super Effective: Togepi
Perhaps even have an option where you can click if your Pokemon has Mold Breaker/Turboblaze/Teravolt. This can help those users who don't know what Mold Breaker and its brothers can do.
Fire Dragon Turboblaze
Normal Effectiveness: Heatran (Flame Body), Heatran (Flash Fire)