Each time you go through this loop your Nantuko Husk gets bigger, allowing for a one-hit kill, or you can combo along with Diregraf Colossus for infinite tokens, with Plague Belcher for unlimited damage, or with Champion of the Perished for another infinitely large creature
Once per turn, Archfiends Staff of Despair allows you to decrease the attack of all monsters your opponent controls, by half the attack of the equipped monsters, until the end of the turn
Its not exactly clear why there are Commander precons for a set thats supposedly designed for Modern, but Wizards is clearly trying to appeal to as many audiences as possible here
We always recommend you start off with an MTG precon before learning how to build a Commander deck
Bloodstained Mire gives extra red and green sources, bumping the green sources to twelve, which is plenty for only three green cards in the maindeck