OoC: why, I would've suggested you to do that if you didn't figure it out yourself.
Alden quickly ordered his Flareon to get away from the smog, to avoid the poisoning. Luckily the Fire Pokemon managed to succeed in evading the nasty side-effect. The train er then racked his brain, trying to find out a way to penetrate the toxic shield- then, it dawned on him. Toxic attacks are flammable!
"Flareon, use Flamethrower at the Slugma!" he ordered, as Flareon gave him a doubtful look. "Trust me on this one."
Flareon decided not to defy his trainer, as he had no reason to. His bushy tail flared up, and the golden mane seemed alight with new energy as the Pokemon prepared the flames inside his body.
The attack was fired, blazing embers rotating in the air to the Slugma, who by then had finished performing the defensive move and had started preparing another move. It braced for the incoming flames as they ignited the poisonous screen, creating a wall of flames that blocked the view.
Slugma was breathing heavily after the attack hit. It wasn't very effective, but still strong. Protected by the firewall, the Pokemon started emitting heat, shedding lava to create a new "skin", trying to heal up.
Area effect: Ash Rain.
Uneven terrain. Entrance of a cave. The smogscreen was ignited, and is now a flame wall that blocks the view of Slugma.
Slugma (??/??/??) 25.10%
(Defense raised) ]Recover[
Name: Alden Umstar
Items: Park Ball x5, Super Ball x4, Full Heal x2, Max Potion x3
Female Calm Umbreon (Synchronize) 100%
Extra Moves: Toxic TM
~Male Adamant Flareon (Flash Fire) 86.37%
#1 - Timid Male Geodude (Rock Head) - Captured.
#2 - Geodude - Trainer Fled.
#3 - Cubone - Trainer Fled.
#4 - Diglett - Trainer Fled.