108 candy: Super Repel + 24 seconds.
Birds Double: Finish off Pelipper with Cform if he's the only one alive and if he was faster than Doduo (same speed) by healing or using a potential elixer on Swampert. This would be done on Swampert's turn. Saves a strength and potential trolling.
Darius: Switch into Swablu instead of Castform. Use it as fodder. Send Swampert back out. Time loss: (to be determined).
TnL gym: Don't fight the first two trainers individually if your Castform has dangerously low Sp Def. This gives it lvl 28.
Selling 5 Pokéballs: useful if you want an extra Repel or Super Repel (lake candy), an extra X Special, an extra X Speed, etc.