Mulligans
A modern version of the old, good freeze mage. A lot of board clears, removal, tempo swing, and burst potential. The biggest advantage is that nobody expects you to play a deck like this one, so you can surprise a lot of players with both burst and board control.
Warrior
Probably the weakest matchup, you can replace bombs with Elysiana, heal with Applebaum and Zilliax, but warrior can easily armor up out of the fireball range and brawl if you manage to take over the board. Your hope is to Alexstrasza your opponent, punch him in the face a couple of times and finish him off with spells and Warmages.
Druid
This deck doesn’t do great against tokens, but neither do other decks. If you manage to clear tokens until dropping astromancer on an empty board, you win.
Rogue
A pretty good matchup, you can remove weapons, kill hench clan thugs with frostbolts, swing the board with Warmages and Doomsayers.
Warlock
A strong matchup, boardclears destroy zoo. Your opponent will need rushing sea giants to win.
Shaman
The easiest matchup. You clear the board, take control over it and win.