So You Want to Open a TCG Store
I'd suggest removing four Mountains, three Swamps, and three Islands to make room for: Xander's Lounge Darkwater Catacombs Shadowblood Ridge Temple of Deceit Temple of Malice Temple of Epiphany Temple of Epiphany Crypt of the Eternals Vivid Crag Vivid Creek Vivid Marsh Mid-Budget Mana Base You can improve the mana base much more by removing 12 of the basic lands (four of each) and three of the worst dual-land cycle (Choked Estuary, Foreboding Ruins, Frostboil Snarl)
Playing one card, named Cleanse, causes all black creatures in play to be destroyed. Another, called Crusade, provides gains to all white creatures. The racist imagery of the Invoke Prejudice card is especially obvious
Combine it with Bloomburrows Starscape Cleric (and other options), and then all you need to do is make the opponent lose a single life to start a combination that wins on the spot
These were all printed in Commander Deck brews, by the by