Instead of directly stopping creatures from attacking you, it forces your opponents to make a tough choiceeither pay they 3 mana for each attacking creature, or they let you create a 3/3 Ogre token for each one
When paired with cards like Moana, Of Motunui, you can challenge opposing characters in waves and reduce how much damage you take overall, though you may need several in play to eliminate stronger opponents
However, it should be noted that most MTG tournaments dont allow Mox gems because of their rarity and strength
+ Choose a creature you control
This is a great template for the current UB meta decks, being able to play King T'Challa on your opponent's turn if you leave mana untapped and possibly even in response to them casting a spell that allows them to draw a card
It shows he is a voice actor, brings something to his videos but get stale after a while