If its toughness is lower than the attacking creatures power, the blocking creature is destroyed and removed from the playing field
They cant be legendary so you cant return Shigeki itself or planeswalkers like Lolth, Spider Queen or Sorin the Mirthless
Drawing a Mox early gives a player an early mana advantage over their opponent and mana advantages often win in M:TG
A 4-mana 6/6 that always makes you sacrifice a creature when it enters isnt worth it except in decks with good sacrifice fodder
A global community of artists, institutions, scientists and game enthusiasts have created numerous iterations of the gameincluding decks featuring west coast marine life, dinosaurs, microbes, and even a Women in Science version created by Westcoast Women in Engineering, Science and Technology
2 mana nets you a treasure token for every artifact and enchantment your opponents have on the battlefield, and since the effect is stapled to a creature, recursion and blink effects make its enter the battlefield trigger ripe for repetition