For cards in a perfect condition, or those recently pulled from a booster, the exceptional Gold Label & Black Label (CCC 10), indicative of a card in pristine condition, are accompanied by a very sharp increase in value compared to an ungraded version
The idea here is that you would keep gaining more mana, and if you couldn't pay it, you would keep taking more damage
Ruinous Ultimatum
Additionally, it can protect any of your creatures by making them indestructible, for just and a Food token
Further Upgrades The first cards I'd pick up to further juice up the deck would be untapped mana-fixing lands: Watery Grave, Shipwreck Marsh, Underground River, Morphic Pool, Darkslick Shores, Polluted Delta, Sunken Ruins, Undercity Sewers, Urborg, Tomb of Yawgmoth and then maybe a couple more Island / Swamp fetches