Necklace of Death

Whenever Necklace of death enters the battlefield, return target black creature with summoning cost {4} or less onto the battlefield
{1}{b}, {t}: deal 2 damage to target creature
{3}{b}, sacrifice Necklace of Death: return target creature from your graveyard into your hand. Its summoning cost is reduced by {2}
"Death will come one day. There is even jewellery with this theme!"