In Hearthstone, each Hero Power costs 2 mana. The card Maiden of the Lake for instance sets the mana cost to 1 while it is active on the board.
I know that having 2 of them does not make the Hero Power free, as both cards will set the mana cost to 1 meaning one of them has no effect at all.
So are there cards that make the hero power free or are there cards that reduce the (current) mana cost by 1?
Just a beginner by the way, so I might just have missed some cards.