Ok I battled this team and won, but it was pretty good :D so I think some improvements are needed to make it better :D
Politoed is good as this is a rain team. But why Focus Blast? This isn't a offensive Politoed, so there is no need for it. change it for Toxic or Hypnosis (I recommend Toxic, because Hypnosis has way low accuracy) Refresh is also good if you want to get rid of poison. But if you want,you can change it to Protect so you can stall with Toxic and Protect with Leftovers. Change the nature to Bold.
Yeah this is also a great Pokemon :) Though you need to fit wish in there. Maybe for Acid Armor? You don't seem to need it a lot with the decent buil it provides. But I see that your team needs a Pokemon to take in your electric attacks, which are predictable enough, so I would recommend this guy: Gastrodon.
Gastrodon @ Leftovers / Trait: Storm Drain / 252 HP , 4 SpA , 252 SpD / Modest Nature (+SpA, -Atk)
- Earth Power
Earth Power is your STAB, and it takes care of electric types. Scald is powerful STAB, and it also gets Rain boost. Toxic is to stall the opponent and Recover is for healing. Another option on this guy is for her to have Ice Beam over Toxic (it's what I have) but that;s our choice. Either is fine.
Toxicroak is great, though one option is for you to replace Ice Punch for Substitute. Get your Substitute and then start using Swords dance. if you've finished getting the amount you want, substitute again and then Use Drain Punch for HP of if you are sure that the opponent is going to attack, Sucker Punch! :D Overall, this Toxicroak is amazing.
Hmmm.....Cresseila is good enough, but it doesn't abuse Rain at all. Maybe replace it for Jirachi?
Jirachi @ Leftovers / Trait: Serene Grace / EVs: 128 Def , 252 Special Attack , 128 Special Defense / Modest Nature (+SpA, -Atk)
- Stealth Rock/Wish
- Calm Mind
Jirachi is great for Rocks, though if you want some extra HP, go with Wish. Clam Mind to boost your special Attack and Special Defense. Thunder abuses rain and Psychic is STAb. those two paired up with Thunder is amazing :)
Though if you want to to keep BL2 then that Cresselia is good as it is :D
Tornadus-T is good as it is but Choice Specs might also be good on it. You could consider Thunderus-T though. I won't post a moveset because I think you know what the moveset is, it's pretty close to that one. Keep in mind that Stone Edge KO's both of them. (I know it KO's Thunderus with a little STAb but I'm pretty sure it KO's tonadus too) If you want a moveset, comment and I'll post one.
TBH, I'm not a big fan of Klingklang, and it doesn't help your team much. I would definitely replace it. (I think you did in our battle...) Here would be a good replacement;
I'm going to choose a RU Pokemon, because Klingklang is in RU.
Electrivire @ Life Orb / Trait: Motor Drive / EVs: 252 Attack / 4 SpD , 252 Speed / Adamant Nature (+Atk, -SpA)
- Thunderpunch/Wild Charge
- Ice Punch
- Cross Chop
Decent set. If you don't want recol go with Thunderpunch. If you need more power go with Wild Charge but there's recoil. Rest is self explanatory.