Nominating Froslass for A-/B+
As it is, while outclassed by Deoxys-S, one of the most amazing Spikers, good amount of speed, unpredictable, versatile, fast Destiny Bond, fast Taunt, and can run T-Wave to get "Free turns". It also can run some quite gimmicky sets such as T-Wave + Hex; it also is the second best Sub-Disable user after Gengar, except that Froslass can use the free turns for setting spikes.
I think Froslass fits greatly here, it does give the opponent free turns using Spikes, it cannot create free turns easily, but it can still do it, between T-Wave, Disable, Switcheroo, and Taunt, it can easily set up minimum of 2 layers of spikes thnx to Focus Sash, it may be completely flat out stopped by faster taunt, but outside of Crobat, it is faster than all the pokemons that would taunt/defog as regular bases.
Froslass can switcheroo it's scarf to gain a free turns, it can taunt the pokemons setting up, he has to switch so that's a 1 turn, it can disable a choiced pokemons so that's also a free turn, So Disable/Switcheroo/Taunt/Spikes can put 3 layers of spikes. Even though it loses it's focus Sash, it is a bit risky.
OR you can have Taunt/Disable/T-Wave/Spikes w/ Focus Sash, you can also layer 3 layers of spikes.
of course, you can use Froslass for support and just taking down at least 1 pokemons from the opponent, with T-Wave/Disable/Destiny Bond/Taunt or Spikes, you are either setting minimum 2 layers of spikes, crippling foes, making your pokemons faster (T-Wave), or taking minimum 1 pokemon down thnx to fast speed or Destiny Knot.