I jsut beat Wynonia and all I have is Vigoroth, Marshtomp, Altaria, and Gardevior. Now I do have a Breloom that I have been phasing out as it's ill natured and is starting to become a problem. any advice on what I should consider adding to my team?

Get a defensive pokemon, like Skarmory or Aggron. You can catch Skarmory at Route 113 if you got the patience, or Aron at deeper part of Granite Cave west of Dewford. And level up your pokemon to balanced level, because it seems that Vigoroth and Marshtomp are between level 30-35, but your Altaria seems like level 42 or higher.

And for nature, i suggest breeding it with the same pokemon with different gender. If the mother has the nature you're looking for, make it hold an Everstone.

Hope this help.

Maybe you can balance your team out?

Add an electric: Manetric or Magenton?

Add another grass pokemon: Cacturne?