Yep, I know exactly what you're talking about EBeast. Rain and Sun offense is so easy to win. Agent Dell's mixed Floatzel 2HKOs walls of NU, while still holding a respectable speed of 270 outside of Rain. It sucks that Sucker Punch ruins it, though, so fitting Aqua Jet would be cool. Ludicolo is a no-brainer, with 3 perfect offensive coverage to have a spare slot for Substitute to foil Sucker Punchs. Prankster Rain Dance and Encore support from Volbeat helps a ton, and is a key to Rain offense's success, imo. I think EBeast and I talked before about how Swords Dance Samurott fits well on these teams, because Swift Swimmers are often specially based, forcing the opponent to fodder physical walls to keep special tanks healthy. Once physical walls are replaced, let SD Samurott rip loose! Special Samurott in Rain is certainly frightening on its own, though.
I haven't tried using a Sunny Day Team, but I can only imagine it working even better than Rain, since it can easily bypass Amoonguss and Alommomola that can trouble Rain teams. Victreebel and Scarf Solar Power Zard rips through RU, and I can imagine doing an even easier job down here, seeing how there are lesser answers to them. Nothings short of Carracosta is going to stop CB Emboar's Flare Blitz while sunny! Speaking of Emboar, Sunny Day teams needs to fend themselves from opposing Emboars, which may take advantage of the weather. Flash Fire mons like Morning Sun Rapidash and mixed Guts Flareon sounds like potent threats that can deal with Emboar. Giving Charizard Air Slash would help, too. Sun Teams have their own Prankster Summoner in Whimsicott, which also has Taunt to prevent Rocks from going up, which is vital for Sun teams.