I want to see a brawl where, you create your deck but when you mulligan, you never draw. You have to play the entire game with just what you mulliganed. It would be shorter matches but I think it would be fun.
Every minion with text is silenced and given random text from another card in the game before entering play but after you play it.
You could play a Wisp that miraculously clears your board and discards your hand or gains taunt and divine shield. Your Anub'arak could deal 4 damage to itself. Your Flamewaker could give adjacent minions +1 spell damage.
I am a big fan of the random brawls where you don't have to create a deck or if you do, you won't control most of the elements in the deck.
Erect a wall between the two sides of the board like in the middle of the board. Essentially, the wall would be a bunch of neutral 0 attack taunts. you can only attack your opponent or enemy minions that you can see through the different openings you make in the walls. you attack the walls like attacking anything else. Sections of the wall respawn after 2 turns.
you would really have to pay attention to how many minions you have on the board and how to get to your opponent.
Example: If 1 minion was on the board and broke the middle section of the wall but then that player played another minion to have 2 minions, they couldn't attack the enemy hero because they dont have a direct shot at the hero, they could attack enemies that are on their diagonals so if there were 2 or 4 or 6 minions on the enemy's side but aside from that, they couldn't attack or they would just have to open another wall.