Acrobatics/Unburden Sceptile sucks imo, and the most popular set is the Special Sweeper. The Unburden set is walled by way more stuff than the special set, and lacks immediate power without a Swords Dance. The best set right now is:
Sceptile (M) @ Leftovers
EVs: 60 HP / 252 SAtk / 196 Spd
Timid Nature (+Spd, -Atk)
- Focus Blast
- Giga Drain
- Hidden Power [Rock]
Sceptile has great coverage with Focus Blast, Giga Drain, and HP Rock. It also provides great resistances for any team, as it is (obviously) a Grass-type. The reason I use Substitute is that Sceptile can set up on so much such as Lanturn and Pokemon using status moves like Ferroseed. With its great coverage and Speed, Sceptile has an easier time sweeping behind a Substitute as it can take a hit while damaging the foe. I use Leftovers so Sceptile can make more Substitutes, and I think that Life Orb really damages Sceptile's longevity. If you want to run Life Orb, it'd probably be better to use Leaf Storm instead of Substitute for more power.
The only other Sceptile set that I like is august's set, as it's a huge surprise and it'll take a while for the opponent to figure out what walls it. I won't elaborate because I'm sure he'll make a post about it
Sceptile is one of my favorite mons in RU, and is definitely one of the best now that RU is so fast-paced.