Once the card is revealed or at game's end, the card goes to its owner's graveyard
Its an Energy-based board sweeper, and unlike Localized Destruction, it can also go after artifacts and enchantments
Juggernauts matter isnt really a thing, so Graaz is best built around a supporting cast of cheap, scampy creature tokens like servos, thopters, and myr
There is also the issue of playing into bounce and exile removal when you need to be able to cash it in
you cannot Special Summon monsters from the Extra Deck for the rest of this turn, except Machine-Type Synchro Monsters, also, destroy that card, and if you do, Special Summon 1 "Crystron" Tuner from your Deck
Draw Card draw is where most of the black in this Mardu deck comes in, with cards like Phyrexian Arena , Night's Whisper, Read the Bones , and Sign in Blood all giving us a few cards here and there