Trying to keep pace with a Hierarch when playing a highly aggressive deck is a head slumping experience, and due to the lack of competition most decks with access to the colored mana would choose this over other creatures in the same price range
Only four creatures have this effect baked-in, and two other permanents can grant it
Already you may want to go with cards with expensive equip costs like Colossus Hammer
You choose all of your modes at once
Traditional and Premier Draft entries both go for 1,500 gems, while Sealed events cost 2,000 gems to enter
Any time a legendary creature with mana value 4 or greater enters under your control, you become the monarch, and if you still hold the crown at your end step, you get two 1/1 soldiers for more value