Shiftry

Chlorophyll
Speed doubles in sun.
Early Bird
Reduces sleep time by 50%.
Type Tier
Grass / Dark UU
Level 100 Statistics (see level 5, 50, 100)
Min- Min Max Max+
HP
90
- 321 384 -
Atk
100
212 236 299 328
Def
60
140 156 219 240
SpA
90
194 216 279 306
SpD
60
140 156 219 240
Spe
80
176 196 259 284

Overview

It is indeed a very cool UU, and has some potential to be used in OU play. You'll have trouble getting it in, but once you do and get the Sunny Day, it's a menace to get rid of. I don't know why it got Grass-type since it's a Tengu, a bird-like evil spirit, but it's a good thing it did. It also has some use in Ubers, paired with Groudon for the Speed boost, so it can just abuse Shadow Ball to hit all the Psychic Ubers.

Name Item Ability Nature

Choice Band

Choice Band Early Bird Adamant
Moveset EVs
~ Brick Break
~ Shadow Ball
~ Quick Attack / Fake Out
~ Explosion
60 HP / 252 Atk / 196 Spe

Nothing resists Shadow Ball + Brick Break, Choice Band Explosion HURTS and Quick Attack / Fake Out if you need to finish off something. You need prediction, like every Choice Bander. The lack of STAB hurts, but you have the element of unpredictability. Ability won't matter all that much, Early Bird can help sopping up Sleep status and still be able to wake up before the match is over, Chlorophyll if you can get your opponent or one of your other Pokémon to use Sunny Day.

Name Item Ability Nature

Swords Dance

Leftovers Early Bird Adamant
Moveset EVs
~ Brick Break
~ Shadow Ball
~ Swords Dance
~ Explosion
60 HP / 252 Atk / 196 Spe

A lot like the last set, except with Swords Dance this time over Choice Band.

Other Options

Growth and Synthesis, but don't use them, they are just the other mediocre moves Shiftry learns. Better go with the above sets.