What is the best card to include in Platinum Arena decks?

[ginandtonic]

I am sure I didn't pick the best of each quanta, but it should be interesting nonetheless...

[Keeps]

My Others are two, but I couldn't chose two, I'll list them anyways, Blackhole, SoD)
In addition I chose: Discord and Purify 

Only a subset of decks make good Plat farmers, and after those decks that can't cut it against the plat farmers are left out all that remains are other decks.
Here is my general catagory of decks that people will likely use for plat farms.

Decks using SoSa, (purify is hard shutdown on that)
Decks using Poison, (purify is hard shutdown on that)
Mono or Duel Rushes (Discord will slow that down hardcore)
Rainbows and SNBows (Blackhole)
OTKs (SoD prevents that unless it's a crazy OTK)
Infinite turn decks (usually rainbow, blackhole here can allow you to outrush it.)

So my suggestion is never mono in Platinum, always duel or more...
Running SoF rush, toss in some discords and make them fly, or unicorns and SoDs.
Running a death rush, toss in some water, and purifies to make it great.
Running a fire stall?, toss in some light towers and SoDs, you won't regret it.