Sceptile


Type: Grass
Base Stats-
70 HP / 85 Atk / 65 Def / 120 Spd / 105 SAtk / 85 SDef

Weaknesses: Poison, Ice, Fire, Flying, Bug
Resistances: Grass, Water, Electric, Ground
Immunities: None

Abilities-
Overgrow: When Sceptile's health is below 1/3, his grass moves get a boost.

Sub Seeder

Sceptile @ Leftovers
Ability: Overgrow
EVs: 56 HP / 200 Def / 252 Spd
Timid Nature (+Spd, -Atk)
- Substitute
- Leech Seed
- Grass Knot
- Hidden Power [Fire / Ice]

SubSeeding is possibly the most evil thing a grass type can do, and Sceptile does it best. The idea is to come in on something that will switch out on you, set up a Substitute, and then Leech Seed. Every time they try to break your sub, just set up another one. With both Leech Seed and Leftovers healing you, you won't lose health from the substitutes. Grass Knot is your standard STAB move, and is useful for all the heavy Pokemon found in OU. Hidden Power [Fire] is there to take care of steel types like Skarmory, while Ice will hit dragon types like Salamence and Garchomp.

Choice Specs

Sceptile @ Choice Specs
Ability: Overgrow
EVs: 4 HP / 252 SAtk / 252 Spd
Timid Nature (+Spd, -Atk)
- Leaf Storm
- Hidden Power [Fire] / Focus Blast
- Grass Knot
- Hidden Power [Ice] / Dragon Pulse

Sceptile has the speed and special attack to pull this set off, so why not? Hidden Power [Fire] is for steel types, or you can use Focus Blast which also hits Blissey harder. Hidden Power [Ice] is for dragons. Obviously, you can't have 2 Hidden Powers on the same set, so if you use [Fire], you need to use Dragon Pulse in place of [Ice]. Grass Knot is STAB, and Leaf Strom is sort of a Specsmence-hit-and-run type strategy.

Choice Band

Sceptile @ Choice Band
Ability: Overgrow
EVs: 4 HP / 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Leaf Blade
- Dragon Claw
- Earthquake / Brick Break
- Thunderpunch / Pursuit

Sceptile may not have the best attack stat, but it does have a lot of physical moves to play with, and he can hit surprisingly hard with a Choice Band. Leaf Blade is your standard strong STAB move, and Dragon Claw covers dragon types like Salamence and Dragonite trying to wall you. Earthquake and Brick Break cover steel types to an extent. Thunderpunch is an excellent choice for covering both Skarmory and Gyarados, but Pursuit can be used to take care of Gengar.

Swords Dance

Sceptile @ Choice Band
Ability: Overgrow
EVs: 4 HP / 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Leaf Blade
- Dragon Claw
- Brick Break / Earthquake / Thunderpunch
- Swords Dance

A similar premise to the previous set, but requires slightly less prediction, but also takes away a move slot. Brick Break and Earthquake are probably the best moves to choose for the third slot, because without it, all steel types will wall you. However, you can still use Thunderpunch for Skarmory and Gyarados if desired, but I don't really recommend it.


Other Options:
For the first set, you can go physical instead if desired, in which case you would replace Grass Know with Leaf Blade and Hidden Power with X-Scissor.
Speaking of X-Scissor, it's a great option on any physical set to take care of Grass types who try to block Leech Seed, or wall your grass attacks.

Endeavor would be an excellent option, since Sceptile has the speed to use the Endeavor+Endure set, but the metagame is so rampant with Sandstorm that I don't recommend it.

Rock Slide counters Flying pokemon, but you could just use Thunderpunch for that.

Counter could be fun to use in conjunction with Focus Sash.

EVs / Nature: If you do decide to go Physical on the SubSeed set, then change your nature to Jolly.

Counters:
Against the subseeder, a grass types can block leech seed, but can't really do much to Sceptile after that.
Anything faster than Sceptile.
U-Turn.
Bronzong and Skarmory work, but need to watch out for HP [Fire].

Opinion: Yay sceptile! SHOUT OUT TO ANNIHILATOR ZERO (a.k.a Sceptile abuser master).