So, when and where should you be slotting this into your deck
This effectively equates to being able to Forage twice, and it draws you a card in the process
Pairing this with cantrips (cards that replace themselves and usually offer some form of card selection) allows you to both quickly fill your graveyard for cards like Murktide Regent or Underworld Breach and make sure that you are drawing good cards every turn
If you choose not to cast any of the exiled nonland cards (either because you can't or don't want to), those cards will remain in exile as well
At just three mana, you can easily accelerate it out with other cards like Chrome Mox and Lotus Petal, meaning the creature can reliably be cast on turn two (or even on the first turn, depending on your draws)
Wizards has said it will maintain Standard as-is, but its hard not to have concerns about the whole thing for those who want things to stay the same