Electromagnetic emissions from gravitational wave sources such as supermassive black hole binaries will carry additional information of the environment in which the source is embedded. Using techniques from numerical relativity, the coupled Einstein equations with matter fields let us study the dynamical spacetimes of non-vacuum binary mergers in fully non-linear general relativity with matter probing the most dynamic strong regime of the system. We discuss the current understanding of anticipated electromagnetic counterparts from astrophysical environments probing the highly dynamic spacetime surrounding these strong gravitational wave sources.