What UU pokemon are least common BUT have potential?

[Mio]

Try Lilligant, she is absolutely amazing.

Lilligant @ Leftovers/Big Root ( Might try Expert Belt, but not Life Orb )

Timid 58 HP/200 S.Atk/252 Speed ( Use "Own Tempo" )

Giga Drain
HP Fire/HP Ground
Sleep Powder
Quiver Dance

The strategy is to either sleep on the first turn, or Quiver. Generally, try to sleep on first turn, but Quiver can be useful if: The opponent will try to switch, or set up on the first turn. If for some reason you think a will-o-wisp is coming, quiver. At that point, you'll be able to out speed basically anything. (Exceptions include scarfed Weavile and Sand Stoutland.)

Don't be afraid to take special attacks after two boosts. Sometimes, it can be helpful to brace yourself for a special attack by quivering, and then next turn when you out speed, either sleep or Drain. By the way, Giga Drain can become ridiculously powerful very quickly, if you face a fire type and have HP Fire, use Giga drain over it.

Any questions?