Лев Эль'Джонсон — был примархомлегиона Тёмных Ангелов, одним из двадцати «сыновей» Императора, которых тот создал на заре Империума, сразу после окончания Эры Раздора. После того как капсулы с примархами разбросало по Галактике, один из них оказался на мире смертиКалибан. Этот мир был полностью покрыт джунглями, которые кишели смертоносными хищниками и прочими опасностями. Там мальчика-дикаря и обнаружил Лютер.

Lion El'Jonson, often times referred to as "the Lion" during his lifetime, known also by the cognomen "The First," and the honourific "Primaris Angelus Mortis," was the primarch of the Ist Legion of Space Marines, the Dark Angels.

Following the events of the Horus Heresy, Jonson and his crusading fleet returned to his homeworld of Caliban. Inexplicably, they were fired upon by the Dark Angel forces garrisoned there under the command of his once-trusted mentor and surrogate father, Luther, who had been entrusted with the custodianship of Caliban in the Lion's absence.

Luther would eventually betray the Lion after allowing himself to be seduced by the offers of Chaos, rallying a good portion of the Dark Angels who had been left behind by their fellows to garrison the Legion's homeworld to his cause and attacking the Lion's fleet as he returned to Caliban.

The titanic struggle between the two former friends resulted in the destruction of Caliban and the loss of the Dark Angels' primarch, as well as the escape of Luther's allies who had sided with the Ruinous Powers.