Well, it's not entirely possible on your own, but what's amazing here is that this happened in Ranked Play.
Turn 1: Play Argent Squire
Opponent Turn 1: Opponent plays Coin, drops Millhouse Manastorm
Turn 2: Well, good thing you didn't have a good early game opening hand. You play TWO Force of Natures and a single Savage Roar. You get six 4/2 treants with charge and a 3/1 Argent Squire with Divine Shield, aside from a hero attack of 3, once you use your hero power.
Sadly, your opponent knew it was a bad choice by then to have played Millhouse.
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