The big problem is that Summon: Esper Maduin is only a 4/4, so not terribly difficult to deal with, and you had to invest six mana to get there
You may put that card on the bottom.) Land Land (CTRL to add secondary) Monarch Monarch (CTRL to add secondary) Protection Protection (CTRL to add secondary) Pump Combat Celebrant If this creature hasn't been exerted this turn, you may exert it as it attacks
Youll gain 4 life when it deals damage, and deathtouch helps make it lethal and intimidating
Your Tarmogoyf deserves better
Either the transform conditions were simple enough to fulfill yourself, or the payoff on the back side wasnt big enough to justify using a card to reach it
Its not an ability often found on Black cards, and having it on your Commander makes it very easy to use, and a really unique way to build a Black Commander deck