GUYS! Some of you guys (not all, don't get me wrong) don't realize that Reshiram has a inferiority complex to Dialga and Palkia when it comes to Mixed sets, as Dialga and Palkia have better physical AND special movepools compared to Reshiram. Unless other people can prove me wrong that Mixed Reshiram can perform better than Mixed Dialga or Palkia, I think that Mixed Sweeping is better left to
Moreover, if you plan on using Mixed Reshiram, a Lonely nature with the same EVs can work. Maxing out both offenses, then 4 Speed EVs to outrun 0 Speed base 90s Pokemon.
Expert Belt is also an option. With Expert Belt, you can 'bluff' a Choice set, as Choice sets are very popular with Reshiram and then proceed to wreak havoc. If the opponent had already caught on already, though, then blow stuff up. However, Life Orb is still a good option, as it gives a consistent boost to Reshiram's attacks, but at the cost of 10% of HP per hit. Because of this, Wish support is greatly appreciated, like from Blissey.
Partners... partners... partners. Mixed Reshiram, Choice Scarf Zekrom, and AgilityGross (Metagross with Agility) are a good trio, as Mixed Reshiram can tear holes in the other opponents team, Choice Scarf Zekrom can revenge kill, and AgilityGross can clean up the opposing team. Also, Rayquaza is a good partner, as a Choice Bander with Extremespeed and whatnot. Basically, Reshiram is splashable in any offensive team not packed with Kyogre.