Lion El'Jonson, the primarch of the Dark Angels, is named after Lionel Johnson, the author of "The Dark Angel." Following the end of the Horus Heresy, El'Jonson returned to Caliban, his homeworld, where he discovered a betrayal by his closest friend Luther and the Dark Angel forces that had been garrisoned with him. El'Jonson subsequently led a Loyalist Dark Angels force against these Traitors, referred to as the Fallen Angels.