A good card for this strategy would be a cEDH staple called Underworld Breach, which makes each nonland card in the user's graveyard have escape, with the escape cost being equal to that card's mana cost plus exiling three cards from the user's graveyard
There are, of course, weaknesses to a mill strategy some players include cards that prevent themselves from losing to an empty library, like Ulamog, the Infinite Gyre
As your creatures deal combat damage to your foes, you draw cards, nice card flow, and synergy with the mass trample giving Brawn or Filth with Urborg or against folks with Swamps naturally
Youll still have to pay half as much for a CE/IE Chaos Orb than you would for an Unlimited Orb, and thats mainly due to its popularity in the Old School format
Corviknight ex takes 20 additional damage from Fire-type attacks
Traditional foil Special Guests cards and dragonscale foil fetch lands are available in Collector Boosters