EVs: 252 S.attack, 220 Speed, 36 Hp
Volt-switch: STAB switch
Thunder-wave and Volt-switch is a frustrating combo that is guaranteed to make your opponent annoyed. Grass-knot is for heavy ground types and HP(Ice) is for Ground types that are not weak to grass but 4x weak to ice eg. Flygon, Garchomp, Gliscor.
EVs: 252 Hp, 200 S.def, 58 Def
Toxic-spikes: Status Hazard
Stealth-rock: One of the most annoying concepts Game freak has ever concocted
Spikes: More entry hazards
Rapid-Spin: Clear away there Entry hazards
Very annoying and if they still have the Paralyzed Pokemon in then there is a larger chance of him setting up a lot of entry hazards.
EVs: 252 S.attack, 252 Speed, 6 hp
Thunder-bolt/Veno-shock: Coverage or STAB
Hex is great paired with T-spikes but I cant decide between T-bolt and Veno-shock. Psychic helps get rid of those pesky poison types who remove the T-spikes from the field. Focus-blast takes care of Steel types. Gengar also serves as a rapid spin blocker because of his Ghost typing.
EVs: 252 HP, 200 Defense, 58 S.def
Roar: Switch them out
Scald: STAB and on the off chance they have a steel-type/get rid of the T-spikes
There are few things more annoying than all entry-hazards + a Super-bulky Pokemon with Roar. Suicune also serves as a wall.
EVs: 252 Attack, 136 Speed, 122 Hp
Meteor-mash will be destroying almost everything while Agility gives him 400 speed with one use(I think that is what I calculated if I need more EVs to do that please tell me). Earthquake and Ice-punch will be hurting what Meteor-mash does not.
EVs: 252 Attack, 252 Speed, 6 Hp
Protect: Stall and boost
Protect gives Toxic a chance to do some more damage and lets Sharpedo gain speed. Aqua-jet is very important because many Pokemon also have priority so you will need this too kill them and because there are a bunch of entry hazards it will be likely that you dont need the extra power of Waterfall.