Since we both have bad teams, I'll write how I did it:
First round: Light Screen and field changing attack. (I used Meowstic and Manectric)
Secound step: Defeat Gardevoir and then the doggo. (I used Meowstic and Pyroar after Manectric died)
Third step: One shot the cotton poke with a fire poke and one shot the togekiss with an electric poke. (I used Manectric after reviving it while low lvl lapras was out)
Last: When Adrienn only has two pokemon left, use perish song and revive until they are defeated.
I know, lame strategy, but thats the best I can do with my current team (:
As for your team, I'd also suggest you get a steel type and other mons as back up, I'm also working on it.