well if you want ideas for an ORAS team to go with politoad i'd recommend mega swampert for your mega as in the rain he makes every mega including mega salamence cry for their mummy (unless he has like 2 dds up in which case i hope you have some ice type priority on your team). Other than that ludicolo is a good option in the rain and a goodra with either sap sipper to sip up grass moves or hydration to deal with status. Other than this you'll want another pokemon who can set the rain up (maybe rotom wash could do this role alright, i dno just a thought) in order to better cope vs sand or char Y teams who will be swapping the whether away from you. Also ferrothorn might go well since fire's power being weakened by the rain 
