Beat Akara and instantly lost to Maiev in Book of Heroes

After I lowered Akara to enough health, it switched to Maiev, who immediately took a turn to buff all her minions from mostly 1/1’s to 3/3’s and smacked me in the face until I died.

So… I beat the boss, and then the next boss kills me immediately without a chance to take a turn???

Gotta hate it when the boss changes without warning, resulting in big misplays. In my case I decided to Felscream Blast my own field, since I had Il’gynoth and 4 Mo’arg Artificers, thinking the 48 face damage would win me the game. Fortunately, in my case Akama only had that 3/5 Taunt Lifesteal so I managed to recover.