Nothing like playing Mages in Arena as Rogue with no backstabs or eviscerate, just cold bloods (that's the least of my worries tho, I never get any good rogue cards haven't once gotten an Agent)...
Turn 1: Mana Wrym.
My Turn 1: Defias Ringleader
Turn 2: Arcane Missiles (clears both the 2/2 and 2/1), Mirror Image, to the face for 3.
That's basically game over there (on turn 2!), but he had another mirror image for his turn 3 bringing the wyrm up to 4/3 behind 4 taunts. Of course by the time I stabilize the board of the taunts he's got Water Elementals, and fireball in hand, and I'm at around 10 health, so there's absolutely 0 chance. I drafted a ton of low cost things too, but even that 2/1 charge guy couldn't save me in time.
Just can't win sometimes, it's really brutal when you don't draft any class spells to hit creatures behind taunts like Mana Wyrm in Arena.