Heros and making cards


I was thinking it would be cool if you could earn some of the hero’s that you face or play as in single player story mode such as cannoner or time tinkerer. This could be a tavern brawl but I was more thinking if you complete a game of say witchwood you would earn one of the heros randomly and be able to use them in wild or a separate game mode.
Another idea is to have a game mode where you can make cards. Of course that would run the risk of overpowered cards but maybe with a few protective restrictions that could be prevented.
What do you all think of these ideas?