On intense mode, I went with the following one for one match ups.
Gengar -> Mr. Mime. Survived a poison move, one shot with Psychic.
Doublade -> cofagrigus #1. Survived the ghost move thanks to naturally high special defense, one shot with Shadow Ball
Chandelure -> Graveler. Survived Energy Ball with Sturdy, full attack EVs and high natural attack one shot with Earthquake.
Rotom -> cofagrigus #2. Survived Ghostly Wail, one shot with Shadow Ball
Mismagius,Dusclops -> Swawsbuck.
Neither of her last pokemon can do real damage against Swasbuck.
Leech Seed -> Horn Leech to heal and Feint Attack when out of pp. Drink pots against Dusclops, he is super pesky.
In my kill attempt, she switched out Mismagius at about 20 percent health, so when Mismagius came back in I just finished it with any pokemon that was fast.