Help! =]

i have another question. all of my pokemon aren't the nature that is suggested.
i have a..
Dragonite(serious)level67
Venusaur(gentle)level50
Charizard(mild)level51
Blastoise(impish)level54
Aerodactyl(calm)level40
Fortress(calm)level43
do you think i should restart cause they will be bad at competitive battles?
i spent alot of time on these pokemon, and i really dont want to start over but i know it will kick me in the butt in the end.


Also i have been breeding my blastoise and i have 27 squirtles, and im wondering what nature is the best the moves/evs/item i have

Blastoise-leftovers
nature-????
252hp/252def/4spa
-sleep talk
-rest
-hydro pump
-ice beam

Restarting wouldnt really be all that bad. IF you want your team to be the best that they can be then I'd restart because natures do play an important role in your stats because they add to a specific IV and subtract from a specific IV. If I were you I would probably start over. As for your blastoise judging from what you have as the moveset you'll probably want a nature to boost his special attack. Modest nature would probably be your best bet because it boosts your special attack and lowers your physical attack. Your blastoise seems like it is suppost to be a weaker special sweeper maybe even a late game sweeper? It's hard to tell. I'd be able to help more if youd explain how its going to be used. I used my blastoise for support in OU and it worked very well. Here's what my blastoise is you might want to try it out too.

Blastoise
Item: leftovers
Nature: bold
Moves: hydro pump, yawn, rapid spin, toxic
EV': 252 defense, 252 special defense, 4 HP

Yawn can force your opponent to switch or end up asleep the next turn and toxic is great for crippling enemy walls and hindering sweepers while rapid spin is GREAT because it destroys stealth rock, spikes, toxic spikes, and leech seed that your enemy has used on you.
You'll probably want surf instead of hydro pump. I just used hydro link because let's face it why have cannons on your back if you're not going to use them right? Hahaha. If you've got any questions at all feel free to email me.

this blastoise is a utility, or a delay