Universe: Lovecraft horror
The originator of the group, it was Cthulhu who found the means to communicate across the universes and contact his equals in other universes.
Cthulhu is the high priest of the Great Old Ones, unnatural alien beings who ruled the Earth before humanity formed, worshipped as gods by some misguided people. It is said that They will return, causing worldwide insanity and mindless violence before finally displacing humanity forever.
He currently lies "dead but dreaming" in the city of R'lyeh, a place of non-Euclidean madness presently (and mercifully) sunken below the depths of the Pacific Ocean, where he influences the entire universe through his dark dreams.
Due to issues around how to pronounce his name, he is usually called Lu.
Universe: Modern Christian.
Lucifer was the first being contacted by Cthulhu, and poker was in fact his suggestion.
Lucifer Morningstar, aka Satan, aka Abaddon, aka Beelzebub, aka Apollyon, aka The Devil, and the list goes on. Originally an Angel, fallen from his Gods grace, and cursed for all eternity.
He usually responds to Luke, but will ignore anyone who calls him Lucy.