Sepulcher or Chaos

All Black creature spells cost {b} less to cast if you control a 'Scion of Rot'.
All Black creature spells cost {b} less to cast if you control a 'Scion of Decay'.
The Scions of Thraeshen'Gard descended upon the hapless corpses of Ettenmare, their hunger growing to the point of near frenzy over the indescribable smell of death.