Reanimation style decks can get away with less, cycling themes with just cycling triggers that cause damage cant will probably need over 50
Avatars Wrath Avatar's Wrath is a cool answer to how youre supposed to squeeze board wipes into your blink decks
Its best friends with Derevi, Empyrial Tactician and Urza, Lord High Artificer, to the point where people usually ask during rule 0 discussions if you play Winter Orb when you present one of these commanders at the table
Some promos have alternate art, full art, or a special foiling
Throw in Galerider Sliver for a spot of evasion, and you can see how easily you can draw a new hand in just a few attacks
It may not look like it, considering that the card is five mana and you can only use each of his abilities once, but it is incredibly easy to ignore Exhaust with some clever deckbuilding