Do you need to win the most rounds or the match as a whole?

If you have money to spare i would suggest Bogdan,Grudj, Baldovino,Rhyno( you can replace Rhyno with Olga or Bogdan with her). I would suggest half deck with Freaks because mono doesn't do much for Freaks.

http://www.urban-rivals.com/en/presets/?id_preset=2507580

http://www.urban-rivals.com/en/presets/?id_preset=2507992

I tried to keep it cheap and low stars(25) I am guessing this is for a Tourny so you will be seeing alot of Freaks and Roots Probably more Roots, so use stop as much as you can. Also stay away from Magda, Erpeto and others like them that get very weak when hit with SOA.

Freaks side
The only one in Freaks with a Stop ability Mira but she should help out alot whenever you see Roots.
Esmeralda can be swapped out if you are worried about SOA, Harleen and Bertha both have 7 power for 2 stars. Olga Noel, or any 8 power card is a good idea to add if you want to make the star count higher, Bogdan, Baldovino are especially good. Maciej and Eve are good in a pinch.

For the other side I picked Jungo for you as they have alot of Stop abilities, Elea, Greow, and Dagouba are all great vs Roots, and Benicio will keep his 8 power agaist anything that will try to drop it. There are many Jungo that are good at winning rounds, but Rodney, Mindy, Ongh, Askai, and Radek are the best and don't lose too much to roots' SOA unlike Odile or Chill will. Jean can easily be added aswell.