My version:
Hover over cards for details, click for permalink
6qq 6qq 6qq 6qq 6s1 6s1 6s1 6s1 6s1 6s1 6u3 6u3 6u3 6u3 6u3 6u3 6u4 6u4 6u4 7gq 7k0 7q5 7q5 7q8 7q8 7ri 7ri 7ri 7ri 7ri 7ri 8pj
Everything should be pretty obvious, but...
Mirror Shield is in, to protect against SoW/Psion decks, as well as preventing Steal/Explosion/SoFo from destroying your DR;
Purify, because so many people build arena decks thinking that Poison/SoSac is powerful (silly people, putting SoSac in the AI's hands!);
Improved Mutation, because 2 SN should mean a beaty, beefy critter on the first/second turn. Also useful against Mono-duo builds (Mutate an opponent's critter, rewind with Eternity, clog hand, win!);
Hourglasses - pure speed.
Play Notes:
Generally, you can rely on SoSe to grant you a cheap creature, if you're locked down and need to stall with Eternity. Don't bother with Purifying regular poison - you should be able to outdamage it pretty easily. Neurotoxin, on the other hand...
NOTHING in this deck is sacred - SoSe gives, as has been mentioned before, a 3-1 card advantage. If it's useful, for even one turn, PLAY IT! If it's not useful, don't sweat discarding -you're more than likely gonna find a better card on the next SoSe play!
Try to save one of the Eternities for the endgame. Often, SoSe will grant weapons, especially Discord (since it's
: ) - use them to bait out Steal, Explosion, and SoFo. You may need that second Eternity, when you're down to your last couple cards vs a stall...
VS. SPECIFIC ARCHETYPES:
Poison Dials SoSac - Play slowly. Wait on your Purify, until the last possible moment. Eternity will generally outstall SoSac, especially if you're quick to rewind any pesky SoFo/Flying Arsenic nonsense that may come up;
Cremation (Lava rush, Dragon rush, Seraphs) - Play out any perms you draw from SoSe, to protect your Eternity as much as you can. Dragons make great bait for Mutation; Lava Golems hate being Rewound. If you can survive the initial 6 turns or so, you should be able to draw a Pandemonium, Fallen Druid, or other effective counter. Just beat 'em at their own game, and rush, rush, rush!
Speedbows - mine's speedier
. Just play out your hand, draw quick, and beat the holy hell out of 'em!
Life rushes - meet Eternity. GG.
I've been using this deck for the past week, farming the Arena, and despite not taking statistics, I can guarantee that it'll destroy Bronze, humiliate Silver, fight hard against Gold, and squeak out wins against Plat. Mostly, though, it's fun - which is important, when you're tired of playing the same old decks. Never the same game twice!