With some careful planning, you can set up some enormously powerful combos
5 Mutilate Toxic Deluge is one of the best board wipes in the entire Commander format, but in Mono-Black decks, they can essentially run two copies of it
Suddenly your Orcish Bowmaster and even Sauron, the Dark Lord himself are Armies, which can grow thanks to Sauron's second ability and trigger his fourth ability
The special thing is that Garruk Relentless is a double-faced card, while Clone isn't
Given its overall power and status as a great combo piece, Hermit Druid is a powerful addition to plenty of Commander decks
There are a lot of creatures and spells being played on both sides of the table, and eventually someone is able to seize and maintain an advantage to win