During the Tyranid invasion, Governor Gregor Vandis fled and left his sector to die. Elena Derosa, once Vandis's adjutant, exposed his cowardice and seized power herself, providing critical aid to the Blood Ravens.
Derosa's actions helped save the sector, but the nobles of Meridian remain leery. Their support has been lukewarm at best. This discontent allowed Eliphas to worm his influence into the militias of House Vandis, converting them into a heretical cult – and the vanguard of the Black Legion.