I would like all of you to read this:
http://www.smogon.com/forums/showthread.php?t=36557
As you should know, Iggybot is one of our community's best and most respected battlers, and this is an exampole of an all-offensive style team that was used in early February, a mere 3 weeks after Deoxys-E's apperance, LONG before the gradual metagame shift. For those of you who don't bother to read it, I'll spell it out for you pretty simply:
Choice Scarf Infernape
Choice Band Gyarados
Choice Scarf Togekiss
Choice Band Snorlax
Life Orb Mamoswine
SubPetaya Yanmega
This is an example of a offensive team, and in fact, this one is more defensive because of Iggy's additon of Snorlax to deal with Starmie. In the thread he says Snorlax is his most replaceable, and I'd imagine is that it is the pokemon essentially "holding" the team's pressure back. Now, this team's strategy is common to all offensive teams - Set the pace and don't let up. Don't give your opponent time to breathe.
So how does this team counter SD Garchomp?? Well, 2 Scarfers, an Ice Sharder, and an intimidate that is immune to Earthquake makes this team pretty Garchomp-proof.
Well, SD Lucario can beat it... well, Gyarados has intimidate, and after intimidate it will fail to KO Togekiss and Mamoswine with Extremespeed, and it can't even KO Yanmega after an SD anyway.
Well, DD Tar? Nope... Choice Scarf Togekiss and Infernape destroy it.
The point is that the team doesn't have solid "counters" to any of these pokemon, but through resistances, immunities, abilities, and Choice Scarfs, this team can handle a multitude of threats should Garchomp or Luke actually get that SD off.
Now, how does Deoxys-E affect this team? Well, it easily OHKOs 4 of the pokemon on the team, the 5th (Togekiss) is OHKOed with the help of SR, and Snorlax is a 1 time switch in only. In fact, most offensive teams don't even have a pokemon like Snorlax because they just use Weavile to get by Starmie. If Snorlax is taking any prior damage, it can't switch into any of Deoxys-E's attacks without being KOed the next turn.
The point of this is to actually provide a VISUAL example since people seem to be having a hard time believing that offensive teams like this existed. Saying "Add Bronzong" will severely detract from the style and "pressure" that the team exerts on the opponent.
Combinations like
Infernape, Weavile, Gyarados, Garchomp / Salamence, Gengar, and Electivire were seen everywhere before Deoxys-E was introduced. And I've said before, Deoxys can rip this team up and theres just no way around it.
One final note I'd like to make about the diffence in Deoxys-E's sweeping potential is the nature of his sweep. Pokemon like Garchomp, Lucario, Tyranitar, and Gyarados all need to
STAT UP TO SET UP A SWEEP AND STILL RUN THE RISK OF BEING OUTSPED (Lucario can just be killed by something that can survive the E-speed) Deoxys-E needs no set up. He comes in and immediately puts a team into defensive mode, which is 100% gamebreaking to other offensive teams, because it effectively destroys the strategy with his entrance into battle. Deoxys-E just comes in and starts fucking shit up, you have no hope to outspeed it barring priority moves, and it doesnt need a boosting turn to beat you, which forces you to risk being killed or switching something in that will be killed. I hope I made my point with EVIDENCE this time.