Have you ever considering adding in Freed from the Real? Freed from the Real on Fatestitcher can combo with Sunken Ruins and Dimir Signet very well for infinite mana using Fatestitcher to untap the land or the artifact, using the blue mana to untap Fatestitcher, and the black mana to produce more mana of either color. It also allows to you tap all of your opponents' permanents.