I'm no expert on Ubers but I found this online and these two seem good to me:
Perhaps the most prolific example of what I am proposing Zoroark is a trickster because of it's ability, Illusion. It is designed to strike first and confuse the opponent through sight alone an impressive ability if played correctly against the enemy team. Zoroark also has access to a number of moves that help define it as a trickster; Night Daze is an attack that also lowers accuracy 40% of the time, plus it can use both sucker punch and U-turn to scout opponents. Zoroark is often classified as a sweeper because of it's strong attack stats, but it's ability and trick moves make it an effective trickster as well.
The ability to transform into any Pokemon, copy their stats except HP, and their movesets, is the epitome of a trickster. Ditto's new ability, imposter, makes it all happen automatically too. Once this is released from the Dream World, Ditto will probably shoot into the uber territory for the first time, as it will become a dangerous adversary, and reliable asset, to a team like a trickster can be.
You should probably check out the other options there.
Hope I helped!