I replace it with antonidas , its bit more dificulty play but he give me somes wins 

U cant replace alex if u want to play freeze mage. It's one of the key cards in this deck.

Trying this list out compared to standard freeze mage... interrrresting deccck

can i add antonidas?

The doomsayer is not a complete loss (great card in this deck don't get me wrong) but you pretty much need the double ice block because of how defenseless this deck is from burst 

Quote from Guldirwinterdew >>

I don't have doomsayer + x1 ice block what shall i sub in?