It costs only 4 mana, it can go into every deck that has a commander with a relevant trigger (which they often do), and if you build a typal strategy, this artifact creature can help you even further
There are certainly downsides here, most notably that exiling your fallen creatures eats into your reanimation options
If youve got a board developed enough for the Overrun effect to finish an opponent, youve likely got sufficient board presence to keep Garruk defended
Whether you're one of those people who like to comment 'first' on everything, or you just like exclusive items, prerelease Pokemon TCG cards might offer some appeal to you
Your proliferate strategy gets a little self-replacing boost
You can only use each effect of "Urshifu the Hidden Master - Single Strike" once per turn