Never seen a Servine used so I'm gonna give you my set for it.
I've tried this set several times, both on the NU ladder and in-game on wifi battles. I find the set to be very effective and surprisingly hard to stop.
Set Name: Hail The Serp!
Servine @Eviolite
Adamant/Jolly/Impish/Careful nature (I personally used Adamant, but I can definitely see any of these working)
Ability: Overgrow
EVs: 4 Atk/252 Def/252 SpD
Moves:
1- Leaf Blade
2- Aqua Tail
3- Leech Seed
4- Coil/Grassy Terrain
Eviolite and the EVs are self explanatory, bulkier is better. Leaf Blade is a solid STAB move, and coming from 60 base Atk, while not the best in the tier, can definitely hurt some neutral and weak-to-it threats such as Basculin, Kabutops, Bibarel (lol) and absolutely nails Whiscash. Aqua Tail is used for coverage, hitting the Fire-types in the tier for SE damage as well as denting the Flying, Poison, and Bug-types that resist Leaf Blade. Leech Seed is used to provide recovery without relying on teammates, since Eviolite > Leftovers. It also can wear down opposing bulky offensive/walls, always a plus. The last slot is up to preference, I tried both: Coil gives you a boosting move to get your attack to a respectable level, defense even higher, and can boost accuracy to rely on Aqua Tail as a plus. Alternatively, Grassy Terrain can heal Servine passively as well as any grounded teammates that switch in. The downside is that grounded opponents get healed, too.
Personaly, I prefer Coil.
All in all, this set, while maybe not so surprising in itself, is definitely unique in being for Servine, a very overlooked Eviolite user.