Sceptile is very fast and has just enough power to send its foes packing. Boasting excellent coverage, Sceptile fares well against many OU threats. Due to its high Speed, Sceptile can revenge kill many rain threats, such as Keldeo, Tornadus, and Thundurus-T. It can also deal a ton of damage to weather inducers with its STAB Leaf Storm. Unfortunately, the good news ends there. Sceptile is the definition of a glass cannon, minus the cannon part, as Sceptile is frail and really not that powerful. For this reason, Sceptile is vulnerable to being both revenge killed and walled. It is walled by numerous common threats, including Celebi, Latias, and Latios. Despite all this, Sceptile manages to fill a niche, albeit a small one, as a fast offensive Grass-type.
This set is the best Sceptile can muster in OU. The biggest issue is getting switching it in, as there is virtually no move Sceptile can switch in on other than Rapid Spin, Scald, and entry hazards. Essentially, what you have to do is make smart double switches and utilize Pokemon that carry U-turn and Volt Switch. Once Sceptile is in, it should generally be hitting something and switching out, as Sceptile usually has to use Leaf Storm to leave much of a mark on the foe. For this reason, keeping constant pressure on the foe is necessary. It is imperative the opponent does not gain any momentum against Sceptile. Leaf Storm, as previously mentioned, is the move Sceptile will use most often, dealing heavy damage to numerous foes, including Jellicent, Rotom-W, Terrakion, Landorus-T, and Garchomp.
However, Leaf Storm doesn't have the best coverage. Hidden Power Ice and Focus Blast are generally the best choices for the second and third slots. Hidden Power Ice hits Latios, Salamence, and Dragonite hard while doing a decent amount of damage to Celebi that aren't running full Special Defense investment. Focus Blast OHKOes Tyranitar and allows Sceptile to hit Ferrothorn, Skarmory, Forretress, and other Steel-types for some damage. Hidden Power Fire and Rock Slide is another decent combination; the former does massive damage to Ferrothorn and Forretress, while the latter OHKOes Volcarona and hits Salamence, Dragonite, and Kyurem-B hard. Finally, Earthquake provides much-needed coverage against Heatran, Jirachi, and Magnezone (unless you wish to rely on Focus Blast).Team Options & Additional Comments >>>
Sceptile can run a SubSeed set to decent effect. The basic premise of the set is to set up a Substitute and stall with Leech Seed, which takes perfect advantage of Sceptile's blazing Speed. However, there are too many Pokemon that counter it in this metagame. Dragon-types, Volcarona, Landorus-T, Gliscor, Dugtrio, Mamoswine, and many others all counter SubSeed Sceptile, making it simply not worth the trouble of getting a free switch-in and setting up. If you do intend to use it, be sure to run a 7 HP IV, as this provides an optimal number for Leftovers recovery. A set with Unburden, a Petaya Berry, and Substitute is slightly more effective. After three Substitutes, Sceptile's Speed is so high that no Pokemon can revenge kill it. After the boost from Petaya Berry, Sceptile is also decently powerful. However, Sceptile's power (or lack thereof) lets it down. Sceptile fails to nab KOs on many threats, and two moves just isn't enough for coverage. An Unburden set with Grass Gem is also interesting, as a Grass Gem-boosted Leaf Storm deals massive damage to a number of Pokemon. However, Sceptile is really lackluster without any boosting item, so this set is not recommended. Finally, Endeavor with a Focus Sash is usable, but Sceptile lacks the movepool to take advantage of it properly.
Checks and Counters
The real issue with Sceptile is that so much of OU can handle it. Despite its high Speed and decent power, many Pokemon simply demolish Sceptile. The easiest way to deal with Sceptile is your stock Choice Scarf or priority user. Examples of good Choice Scarf users that can handle Sceptile include Latios, Salamence, Garchomp, and Kyurem-B. Other variants of Kyurem-B also fare well against Sceptile, as no move Sceptile carries can OHKO Kyurem-B. Between Ice Beam and Dragon Claw, Sceptile is never safe from Kyurem-B's wrath. Yache Berry Garchomp can survive a Hidden Power Ice and hit back hard with Earthquake or Dragon Claw. Breloom and Scizor are the standard priority users, and they wreck Sceptile. Unless Sceptile carries Hidden Power Fire, it will lose 100% of the time to Scizor. Breloom isn't OHKOed by Hidden Power Ice and can therefore come in and Mach Punch Sceptile to death.
Sceptile also has some rather unfortunate issues with certain Pokemon. Basically all sun teams are well-equipped to fight Sceptile, as Pokemon such as Volcarona and Victini can put the hurt on it. Victini is a shaky check though, as Earthquake can KO it after Stealth Rock. Volcarona, on the other hand, only has to worry about the rare Rock Slide. Bulky Gyarados can shut down Sceptile and potentially, depending on the variant, set up on it. Tentacruel really can't do anything to Sceptile and is 2HKOed by Earthquake, but Sceptile can be worn down with Toxic through smart play. Celebi, a Pokemon that is becoming a staple on many teams, is a perfect counter to Sceptile, taking any attack with ease and being able to U-turn Sceptile into oblivion. Amoonguss works similarly. Skarmory can set up Spikes on Sceptile or Brave Bird it to death; Ferrothorn would be able to do the same, but weaknesses to Focus Blast and Hidden Power Fire make its life slightly more difficult. Metagross is bulky enough to take two Earthquakes and can kill Sceptile with a relatively powerful priority Bullet Punch. Gengar is a hard counter to Sceptile and is able to get up a free Substitute on it, which can mean doom for Sceptile's team. Finally, common special walls, such as Blissey, Chansey, Latias, and Zapdos, can take any attack Sceptile might use with ease. In all honesty, although some Pokemon simply cannot find a way to answer it, Sceptile isn't very difficult to beat.