You can't cast Rakdos unless an opponent lost life this turn. Flying, trample Creature spells you cast cost {1} less to cast for each 1 life your opponents have lost this turn.

This land enters tapped. When this land enters, return a land you control to its owner's hand. {T}: Add {B}{R}.

{T}: This creature deals 1 damage to target creature and that creature's controller loses 1 life.