Politoed
Leftovers > Damp Rock. Perish Song > Toxic. Otherwise, Fine.
Kingdra
Kingdra @ Life Orb:
Trait: Swift Swim
EVs: 252 Sp.Atk / 252 Speed / 4 Sp.Def
Modest Nature
- Surf / Draco Meteor / Ice Beam
- Rain Dance
- Hydro Pump
- Dragon Pulse
Kingdra shows you its versatility to summon Rain and to make an excellent usage of these five turns: Having Surf and Hydro Pump in the same set may seem redundant, but actually, it is more impressive than whatever you can be thinking: You have on one hand power, and on the other hand accuracy. Now, if this is not convincing enough, run the duo Draco Meteor and Dragon Pulse for power / accuracy report. If two Dragon Attacks is making you thinking, then Ice Beam will be adding supplementary coverage against Grass type. You have an insane STAB in Hydro Pump with Life Orb and Rain Boost, 2HKOing Salamence at the process.
Beartic
Dive is horrible. Aqua Jet > Dive. Otherwise, pairs nice with Kingdra. Fine.
Raichu
Respecting your choice of favorite Pokémon, I'd say Raichu is decent in the rain. Jolteon and Thundurus-Therian outclasses him by far, but after all, Raichu is your choice. My changes:
I'd say... um... nothing. It is fine.
Ludicolo
Take it out. Kingdra's performing pretty much the same role. I'd say Gyarados performs its role and will Mega-Evolve for having a solid backup. Use a such Gyarados:
Gyarados @ Gyaradosite:
Trait: Mold Breaker
EVs: 252 Atk / 252 Speed / 4 Sp.Def
Jolly Nature
- Dragon Dance
- Waterfall
- Earthquake
- Crunch
Scary Physical Sweeper. Your opponent will simply fear the mighty Gyarados after a boost and you will enjoy its destructive power as well as its ability to counter many common threats, like Mega-Charizard (both form) and Mold Breaker means that Earthquake OHKOes Magnezone.
Bronzong
Come on! There are much better choice for a rain team. I'd suggest you to use Rotom-C. It has the ability to counter Rotom-W and Gastrodon which are threatening to your Rain team, especially the latter. We have to mention Rotom-C for its excellent coverage and synergy in Rain Teams.
Rotom-C @ Choice Specs:
Trait: Levitate
EVs: 252 Sp.Atk / 252 Speed / 4 Sp.Def
Timid Nature
- Trick
- Leaf Storm
- Volt Switch
- Thunder
Special Attacker set. Trick will ruin stall and walls.
Other changes ?
I'd replace Beartic by Ferrothorn or Forretress for hazards. I prefer Forretress because it can spin if needed. Jellicent is an honorable idea to consider. Its wonderful typing, spinblock ability and stall ability makes it so viable in Rain Teams. Volcarona is a surprising choice, yet it can counter Sun teams and use Rain to Hurricane Spam. This guide may help you.
Hope this helps.
~ Sincerely yours, Blitz of Justice.