You get two options and both of them are great: either an enormous army of vampires, or a 10,000 power/ 10,000 toughness dinosaur, with trample, that spawns in already attacking one of your opponents
In terms of their rarity, many of the high-value Charizard cards are rare misprints or unique holofoil or hologram editions of standard cards
You then look at the top X cards of your library and put one into your hand and the rest on the bottom of your library in any order
The hope is that Planar Chaos can counter a few of your opponents spells and your aggressive red advantage allows you to strike hard
You may sacrifice only one creature for Maestros' Totally Safe Hideout's land casualty ability, and you create only one token that's a copy of it
It offers flexible value and sees a lot of play in Standard