Communion from EarthEdit
In 2015, Alexander Luthor, Jr. activated the Scout Ship that was crashed in Metropolis, left behind in the rubble from the Battle of Metropolis using General Zod's Command Key. Once he overrides Zod's Command, he begins learning the knowledge of the universe from the ship, creating Doomsday from Zod's corpse and sending a message out to the stars. Steppenwolf makes contact with Luthor, joining in an alliance to seek out 3 missing Mother Box's that were hidden on Earth thousands of years ago. Luthor explains that conquering Earth should be easier with Superman set to be killed by Doomsday. Before they could finish their communion, Metropolis S.W.A.T. teams arrived to arrest Luthor for his crimes and the transmission ended.
He first appeared in a deleted scene of Batman v Superman entitled "Communion".