Destroy the enemy with a horde of dragons, this deck counters easily the absurdly op druid decks and many board-control oriented or big creature decks.
You can use barnes too as replacement, but I think it's more funny to throw 2 nozdormus when a druid mill deck naturalizes your deathwing (and yes, if you draw a a deathwing during naturalize it goes to the board) . Or a lucky chillmaw vs that mech hunter / manawyrm mage decks.
You can use barnes too, it's a 50/50 to get deathwing but if you succeed it's easier to sacrifice and get that 12/12s to the board.
My mulligan recommendation: Keep all innervates and at least 1 Dreathwing dragonlord, to have synnergy and discover more dragons early. Turn 4 it's nice for the first dragon, that will be the origin of the caos.