Adventurous Impulse is 50% more choice and information than Sleight of Hand and Sleight is a great little card
If you want to frustrate your opponent by denying their best moves and slowly winning the game, this is the deck to purchase first
The only deck I'd run Mirror March in would be the Coin Flip deck where we can dramatically increased its power level with the help of Krark's Thumb, aka Zndrsplt, Eye of Wisdom and Okaun, Eye of Chaos
6th: Twilight Masquerade (TWM) The introduction of Munkidori to the format cannot be understated
It's amazing how many things can be sewed together like this
This is really efficient for what it is, and while it'll be hard to get in with your Hero token, this is really cheap to move around, so you're going to find a creature who can benefit from it