Ok, I guess I shall help you even though you don't have any EVs listed.
I'll talk about your team in general, and then get into more detail. As far as I'm concerned, you seem to have a pretty big Lucario weakness. It can rip through your team with a boosted Close Combat and Extreme Speed. None of your Pokemon are capable of stopping it. If you want to fix your weakness, I suggest using a Pokemon that is capable of surviving a Close Combat and revenge-kill it with an appropriate move. I will get into this later.
You say that this is a Rain Dance team, but I fail to see how this actually is a Rain Dance team. Usually, a Rain Dance team has at least 2 Rain Dance users and Swift Swimmers, and so far, all I see is Bronzong and Floatzel. This isn't a decent Rain Dance team in my opinion. If you want to make it one, I suggest replacing many of your Pokemon, and like before, I will get into this later.
Now, I'll specifically look at your Pokemon one by one.
Bronzong
I'm not really sure this Bronzong is worth it as a lead. I understand why you have Charge Beam and Flash Cannon, but I honestly think that you should use a different moveset that will help with your team. Try using this (I won't include EVs since you don't seem to want them):
Bronzong @ Damp Rock
Impish
-Rain Dance
-Stealth Rock
-Hypnosis
-Explosion
With this set, you are capable of setting up Rain Dance to keep it up for 8 turns, setting up Stealth Rock, inducing sleep, and using Explosion when it's the right time to let your sweepers take the spotlight.
Parasect
Parasect's moveset is pretty... lame to be honest. Parasect in particular doesn't necessarily "fit in" with a Rain Dance themed team, since it doesn't exactly support you in any way, although it does have a nice 4x resist to Grass and Ground and 2x resist to Electric-type attacks thrown at it, but that's besides the point. If you want to continue using Parasect, by all means go right ahead, I'm not stopping you. But, I would just like to suggest a Pokemon.
Toxicroak @ Leftovers
Adamant
-Substitute
-Focus Punch
-Sucker Punch
-Stone Edge
Toxicroak can become a real threat in the rain, since it's capable of healing a bonus of 12.5% health per turn, with Leftovers included, that's a massive 18.5%. You desperately need some powerful physical hitters, since all you really have is Floatzel. SubPunch can be a real pain to anyone, so I think you should look into it. You also have a slight chance at stopping Lucario if your at full health, since you can take on a boosted ExtremeSpeed (I think) and attempt to hit it with two Sucker Punches.
Floatzel
Nothing really pops out at me with this guy, so he's good for now.
Exploud
Well, if you want me to be honest, don't use Exploud. It's slow, relatively weak, easily killed, and it isn't really helping you. It's too slow to use Rain Dance successfully. Now, this is when your Lucario weakness drops. I present to you, this:
Zapdos @ Damp Rock
Bold
-Thunder
-Rain Dance
-Roost
-Hidden Power Grass
Zapdos is one of the best Lucario counters, and this will really help you with your Lucario weakness. It's also an excellent Rain Dance supporter. Thunder is really powerful to.
Ampharos
You're in desperate need of a Swift Swimmer, so I suggest you drop Ampharos for one. Zapdos already does Ampharos' job, so I suggest you use this:
Kingdra @ Life Orb
Naughty
Draco Meteor
Waterfall
Ice Beam
Hydro Pump
Kingdra is an awesome mixed sweeper, especially in the rain. Waterfall is your best bet against Blissey, while Hydro Pump takes care of Hippowdon and Skarmory. Ice Beam helps against Salamence, while Draco Meteor is an awesome STAB attack.
Lanturn
If you want to use Lanturn, I suggest you run the full Parafusion set. Use this moveset:
-Thunder Wave
-Confuse Ray
-Surf
-Thunderbolt
It is nice to paralyze your opponents team to open up for your supporters to use Rain Dance, and it could also help Toxicroak to.
Well, I wrote up a crapload of stuff, so I hope you take this into consideration. Good luck.
