Everything about this guy is boss, who's da boss? Blastoise.
A Water type, so he's a natural beast in the rain with even more jacked up STAB attacks, and he gets a really cool dream world ability to help him out. Lets see how he functions.
Blastoise (M) @ Leftovers
Trait: Rain Dish
EVs: 252 HP / 56 Atk / 120 Def / 80 SDef
Adamant Nature (+Atk, -SAtk)
- Aqua Ring
- Dragon Tail
- Waterfall / Dive
Amazing rain tank might I add, His ability Rain Dish restores his Hp by a chunk every turn, and Leftovers and Aqua Ring too!
Ev's supporting great bulk, and moderately great attack, can't be too perfect.
Aqua Ring as I said, increases his turnly Hp Recovery, Dragon Tail can phaze like nobodies face. Waterfall gives instant hard hitting physical STAB, where Dive lets you stall out Your Aqua Ring boost, but you won't be able to get in a Super Effective blow agaisn't Ground or Rock types without having to worry a bunch about Earthquake killing you.
Blastoise (F) @ Choice Scarf
Trait: Rain Dish
EVs: 8 HP / 40 Def / 252 SAtk / 208 Spd
Modest Nature (+SAtk, -Atk)
- Water Spout
- Hidden Power [Bug]
- Ice Beam
- Focus Blast
Okay, he's playing off of a completely different role here now.
Maxing out his Special attack with 252 Sp Atk Ev's and A Modest Nature, he needs all the help he can get.
Choice scarf and 208 Speed lets him sweet pretty well.
Water Spout is his main sweeping supply, maxed Special attack, STAB and Rain support make it total boss.
HP Bug gives great coverage for him, along with Ice Beam and Focus Blast. And Rain Dish basically is giving him lefties, meaning S-rocks won't screw you too bad.
Overall, he's got a pretty good build for rain.
Rating for the rain - 7.5/10