If you can read from your opponents that they live on self-mill, or rely on a discard outlet, there's an opportunity to make an army out of advisors and win, but otherwise, this is a good way to trigger mill if you like cards such as Deepmuck Desperado, The Water Crystal, and Zellix, Sanity Flayer
This legend isnt that strong outside of some cool synergies, though
Technically speaking, it's legal to play with a deck of more than 60 cards, but at all times your deck must be at least 60 cards and your sideboard must be at most 15 cards
Standard also has two other creatures with this exact mana cost: Craterhoof Behemoth and Ghalta, Stampede Tyrant, which are much more proactive threats