Fire Types wall your set; and, with Fire Spam becoming so common, your set is even worse. It's better to run Hidden Power ROCK instead as it covers its weaknesses better. (Flareon would wall your set to hell and back and is the best in my opinion due to Physical Fire-Type and gargantuan special defense) Although you don't have the ability to hit Ferroseed, you lack a lot of coverage without it. Rock hits Flying, Ice and Fire Types that would otherwise bulk a Giga Drain. Serperior also gets access to Taunt, which is always helpful in any situation, especially for stuff that tries to wall or set up on you (AUDINO)
Personally, I think that Serperior is outclassed by Simisage as a setup sweeper. Simisage has the ability to boost its special attack faster than Serperior, also has access to Overgrow for Giga Drain, and can run three moves because of it. It doesn't need to require Substitute to be effective.
Here's a set I recommend using:
Simisage @ Life Orb / Leftovers
Ability: Overgrow
EVs: 4 HP / 252 SpA / 252 Spe
Timid Nature
- Nasty Plot
- Focus Blast
- Giga Drain
- Hidden Power [Rock]
Why it's better: The reason why I think it's better because it doesn't require Substitute to set up effectively; Hence, like most Nasty Plot sweepers, it can use three moves. This set only gets resisted by Croagunk and Honedge (the only pokes allowed in the Neverused Tier and are both BAD?) and that it provides neat coverage against threats. It can take on the Ferroseed/Seismitoad core with Focus Blast and Giga Drain, respectively; It also has the ability to outspeed Typhlosion by one base point (amazing feat, considering many of them nowadays run Specs instead of Scarf) and that it generally dents walls better than Serperior AND Lilligant without having to worry about coverage. With focus Blast, it can dent steel types that attempt to wall this set. Giga Drain is staple. Hidden Power [Rock] is chosen because it finishes off its almost-perfect coverage and to take out slower threats. Overgrow is amazing on this set to gain back all its HP with a 1.5x boost, which is neat. This poke works like Sceptile but it has the ability to set up in the face of its opponent. It also finds a rather easy time setting up due to its coverage as well and that it can do a lot of damage if unprepared. If it were up to me, it also outclasses Sceptile for the same reasons. It also hits harder than Serperior after a few boosts as well with a naturally higher attack set and a very decent speed stat; meaning that it can outspeed stuff like Serperior. It does have a little trouble with status; but it is able to run a Lum berry if that's a problem. It'll dent, or even sweep unprepared teams if you play it correctly.
First, Lilligant should only be running HP fire as a way to get around Ferroseed. Fire types can just be put to sleep whereas Ferroseed hard walls the HP Rock set to no end.
Second, I don't think that the Serperior set that is the kind of set that is supposed to be featured in this thread. SubCM Serperior isn't a bad set, it has nice bulk and is fast enough to make the set work. This thread should be reserved for sets that are severly outclassed by another set that a mon should be running or for mons just running plainly inefficient sets. The Serperior set listed above fits in neither of these categories.