Magic: The Gathering Novel; Ravinca Book 1 by Cory J. Herndon. Published by Wizards of the Coast.
One guild ravages the streets. Teysa leads another to "cleanse" them. And Agrus Kos doesn't give a damn. But as he watches the guilds nip and tear at each other like snakes . . . something clicks. Now his mind is clear, as are his options. A disaster grows under the city's crowded streets. He knows what he must do.
The Rakdos cultists bloody the streets with a viciousness matched only by the Boros angels attempts to eradicate them.
As it is, the dead outnumber the living. The Guildpact is torn by dissension. And the guildmasters are under attack. Lucky for Ravnica, on a world where ghosts linger, being dead isnt half the excuse Kos would like it to be.