Deathrite Shaman would often take control of a game on its own, and all at the low cost of a single mana
Adventurer's Inn Balamb Garden, SeeD Academy Baron, Airship Kingdom Capital City Clive's Hideaway Crossroads Village Eden, Seat of the Sanctum Gohn, Town of Ruin Gongaga, Reactor Town Guadosalam, Farplane Gateway Insomnia, Crown City Ishgard, the Holy See Jidoor, Aristocratic Capital Lindblum, Industrial Regency Midgar, City of Mako Rabanastre, Royal City Sharlayan, Nation of Scholars Starting Town The Gold Saucer Treno, Dark City Vector, Imperial Capital Windurst, Federation Center Zanarkand, Ancient Metropolis
Its a prominent sideboard piece for control decks going into the mirror
From an esteemed collector, this Black Lotus is the single most valuable normally printed card in the game of Magic printed in a standard set
That's Mr Bone Dragon to you
That said, if your secondary color is only necessary for a few cards, you might be able to get away with it