You do realize that Serperior gets Aqua Tail from the B2/W2 move tutors to at least let it hit Steels neutrally, right?
Anyway:
Tentacruel:
-Swords Dance
-Waterfall
-Poison Jab
-Hydro Pump/Substitute/Rapid Spin
Nature: Lonely/Hasty/Adamant/Jolly
EVs: 252 Atk/80 SAtk/176 Spe or 4 HP/252 Atk/252 Spe
Item: Life Orb/Black Sludge
Ability: Rain Dish/Liquid Ooze
Sure, physical Tentacruel isn't as effective as the standard defensive Tentacruel, but it surprisingly hits hard after a SD boost.
You do realize Serperior is NU where there are almost no viable steel types and the ones that are cannot do jack to you anyway after a Coil (lol metang/probopass etc) ? That Aqua Tail has horrific coverage and synergy with grass moves right ? Actually Dragon Tail helps vs steels you will struggle with more anyway, for example Dragon Tail will hit before Bastoidons Roar so you outphaze it. :/
Also that Tentacruel doesn't work too well anymore sadly as ive tried it. Ferrothorn and Jellicent hard wall it unfortunately. Id probably just use Sub in the last slot so you can at least block Jellicents Wisp and beat non Night Shade ones eventually with poison.
Gothitelle/Magnezone i guess would make a decent partner for it so you could remove Ferrothorn.
Anyway
Forretress @ Leftovers
252 HP / 6 Atk / 252 Sp.Def
Careful Nature
Trait: Sturdy
- Substitute
- Payback
- Spikes / Toxic Spikes
- Rapid Spin
I have been using this set lately and its actually very decent. This gen i feel Payback being nerfed on switch ins is one of Forretress's main reasons for well....sucking. Gyro Ball and Volt Switch simply just do not cut it against spin blockers which means Forry is now a worse spinner compared with last gen.
However, i came up with a way to make Payback still work. The beauty of this set lies in Sub. With a sp.def ev spread Jellicent will NEVER break your Subs with Scald. Which means you can 3hko it with Payback, it will be forced to keep Recovering as you recover with Lefties as it can no longer burn you so now you will at least have a fighting chance with Spikes up against it (this is amplified with SS up). Gengar stands no chance and is nearly OHKO'd with SR up.
Jellicent Scald Vs Forretress: 21.2% - 24.9%
Payback Vs common spin blockers:
Vs 248 / 216+ Jellicent: 30.8% - 36.2%
Vs 0/0 Gengar : 75.9% - 89.7%
Vs 248 / 36 Jellicent: 42.2% - 49.6%
In addition Cofagrigus also cannot break your Sub, burn you OR heal with Pain split so will be forced to switch which will let you spin.
This set also Ko's Chandelure, Golurk etc
The ONLY ghost that really has a chance of beating this set is Sableye (who sadly isnt weak to payback) and maybe Surf / Wisp Jellicent who annoyingly JUST breaks your sub.
The goal of this set is being able to spin consistently whilst standing a fighting chance against Jellicent on its own with hazard support where otherwise it would have to rely on the weak Volt Switch (is bad as it forces you out which is against the goal of spinning)/Tar to Pursuit ghosts.