Reuniclus

Reuniclus is one of the best offensive users of Trick Room in VGC 2012, boasting an excellent Special Attack stat, great bulk, and a fantastic ability in Magic Guard, allowing Reuniclus to ignore damaging weather and make very good use of the one Life Orb allowed per team. It is not without fault though; it is not as bulky as more dedicated Trick Room users and can be OHKOed by certain attacks, such as a Dragon Gem-boosted Draco Meteor from Latios. It is also susceptible to most Steel-types, especially Scizor and Metagross. Reuniclus is also unable to do much about Taunt or Encore. Still, there are few users of Trick Room that are stronger than the little gelatinous embryo, and it should be one of the first Pokemon considered when looking for someone to fill such a role.