I think sun is broken altogether. We have sweepers like Sawsbuck, Tangrowth, and Victreebel running around, but we also have a lot of other stuff. For one, Victini completely breaks sun. V-Create is ridiculous. But there's a very large chance Victini will be banned anyway, so I'll move on. Solar Power Charizard is pretty powerful in UU. Its Fire Blast is more powerful than Victini's V-Create. Let's look at this:
Charizard has a base 120 power move with Solar Power (*1.5), STAB (*1.5), Sun (*1.5), and Specs (*1.5). That's a 607.5 move from a 109 SAtk stat.
Victini has a base 180 power move with STAB (*1.5), Sun (*1.5), and a Band (*1.5). That's a 607.5 power move from a 100 Atk stat.
So Charizard is more powerful, and its stats don't drop. In addition, Charizard has the same speed and is capable of raising it with Dragon Dance, making it even harder to kill. Charizard isn't weak to Sucker Punch or Shadow Sneak while it retains its resistance to Bullet Punch and Mach Punch. Pokemon like Honchkrow and Houndoom can't hard counter Charizard because Charizard has access to other STAB moves like Air Slash. Arguments like "Charizard is SR weak" just aren't enough, because it's not too hard to keep SR off the field.
And it's not just Charizard. Pokemon like Arcanine will destroy with the Sun out. Boosted Flare Blitz, Extremespeed, extra power Morning Sun, Water weakness removed, etc. Can you imagine a Flash Fire Sun Houndoom's Fire Blast? Shit even a Solar Power Sunflora can abuse Solarbeam.
We can ban Chlorophyll+Drought, or Victini+Drought, or Chlorophyll+Victini+Drought, but sun will be broken in UU.
SJ Crew posted this several pages back, and I think it sums up the complex ban discussion.
Why do we need another combo ban to determine what the 'real culprit' is? Victini is used with or without Sun teams and Sun teams are broken even if they don't use Victini. Both are perfectly viable suspects in their own right and should be evaluated separately.
Speaking of which, here are a few examples to highlight just how bad an idea a combo ban would be at this point in time:
1st Round: Ban Victini + Drought
But Charizard is broken!
2nd Round: Ban Victini + Charizard + Drought
But Chlorophyll is broken!
3rd Round: Ban Victini + Charizard + Chlorophyll + Drought
Fire Pokemon dominate the metagame!
Ban Drought
As opposed to:
1st Round: Sun teams are dominating the metagame!
Ban Drought
In reality, a combo ban says we're just looking for a way to waste more time trying to nerf Drought instead of blaming it for the mess it created and getting rid of it from the start.